10-year-old Ben Tennyson begins summer vacation with his 10-year-old cousin Gwen and his grandfather Max. He wanders off and finds an alien pod that has crashed to earth, and within it a watch-like alien artifact. When he reaches to touch it, the watch jumps onto his wrist and refuses to come off, merging with his DNA. Ben accidentally discovers that it can change his form into various alien creatures and quickly learns how to use it, protecting people from robots sent by Vilgax to retrieve the watch. Deciding he can be a real-life superhero, Ben begins a summer full of extraterrestrial adventures for himself, Max and Gwen.

Ben overuses the watch and doesn't have any power left when Dr. Animo, a disgruntled scientist, brings creatures from the Natural History Museum in Washington, D.C. to life. Ben eventually defeats him, and learns that being a hero doesn't always come with rewards.

When Ben and Max go on a fishing trip with Captain Shaw, they encounter the Krakken that lives in the lake. With Gwen's help they find out that the creature is upset because Jonah Melville, a poacher pretending to be an animal lover, is stealing its eggs.

Ben and Max drive to a retirement center to visit Aunt Vera, but find out that evil alien shape-shifters called the Limax are kidnapping and replacing the elderly residents in order to devour them later.

Vilgax hires three alien bounty hunters, Kraab, Sixsix, and Tetrax, to retrieve the Omnitrix. Ben fights Tetrax alone, and Tetrax reveals himself to be the same species as Diamondhead. Tetrax criticizes his lack of strategy in hand-to-hand combat, then aids Ben in warding off Kraab and Sixsix. Realizing that Ben took his words to heart, Tetrax decides to leave him with the Omnitrix and awards him with a hoverboard.

While in a tourist trap town called Sparksville, Ben plays a practical joke that accidentally unleashes Megawatt, small creatures made from electrical energy. Ben must stop them from multiplying out of control and destroying the town with their dangerous pranks, and turns to Heatblast to seal the Megawatts in the world's largest fishbowl.

Straying from Max after an argument, Ben meets and befriends a boy named Kevin, who has the power to absorb any form of energy. Their first misadventure forces Ben to reveal what the Omnitrix is capable of. Kevin suggests that they team up, but he just wants the Omnitrix's power for himself, to get back at those who treated him like a monster. The two fight and Ben chases Kevin off, but Kevin has absorbed some of the energy from the Omnitrix.

Ben as Four Arms reluctantly fights a female thief named Rojo, who injures Max. Ben realizes that his watch makes him a constant target and puts Gwen and Max in danger and leaves them behind, but when he encounters Rojo again, this time controlled by Vilgax's robots and telepathy, it is Max's advice that helps Ben win. Vilgax makes telepathic contact with Upgrade during the battle and threatens him, claiming that he will obtain the Omnitrix some day.

While visiting a travelling circus, Ben fights an evil clown named Zombozo who is draining people's souls through their laughter. Conquering his own fear of clowns, Ben defeats Zombozo by terrifying him as Ghostfreak, and saves his family. Ben admits that he scares himself while fighting as Ghostfreak.

Ben prevents a powerful sorcerer named Hex from stealing the Arkamada Book of Spells. During the fight Ben obtains one of Hex's five magical Charms of Bezel and gives it to Gwen, giving her the supernatural ability of probability/luck manipulation. Using a Mardi Gras costume, Gwen becomes a new superheroine named Lucky Girl and steals Ben's spotlight. Hex lures Gwen into a trap to retrieve the charm and destroy New Orleans, but Gwen smashes the five mystical Charms, so they can't be used for evil.

In a fit of stubbornness, the Omnitrix transforms Ben into Grey Matter and leaves him stuck in that form for far longer than normal. During this time, Grey Matter is captured by an alien-obsessed nerd named Howell Wayneright, before both Gray Matter and Howell are captured by a secret society of modern knights known only as The Organization. The two work together to escape and discover a room filled with extraterrestrial technology, with which The Organization could take over the world. Grey Matter cross-connects three of the objects to trigger an explosion and take down The Organization's base. Enoch, The Organization's leader, orders his men to find information on Ben, Gwen and Max.

A man named Clancy, who has the power to control insects, wants to take revenge on Councilwoman Liang because she wants to tear down the building where he and his insects live. Meanwhile Ben has to deal with the strange side effects a cold has on his alien forms: Wildmutt is unable to see or smell, Four Arms smells horrible, and Heatblast's powers change to freeze powers, which Ben uses to defeat Clancy.

With his wounds finally healed, Vilgax decides to personally retrieve the Omnitrix. He contacts Ben in a dream, which worries Max. Ben ignores Max's warnings not to go alien and flies off to stop trouble along the way, only to encounter Vilgax himself, who captures Ben and brings him aboard his spaceship. Max retrieves weapons from a secret base in Mount Rushmore, and he and Gwen free Ben, but then are held hostage. Max reveals that he activated the ship's self-destruct, and the three escape, leaving Vilgax on the ship as it explodes.

Grandpa Max tells Ben and Gwen about his secret past. He was part of a secret government organization known as The Plumbers that dealt with extra-terrestrial and paranormal phenomenon that others couldn't. The organization was disbanded after he defeated Vilgax for the first time. They run into Max's old partner, Phil, who is still in the business of hunting aliens, though he is now a freelance agent. The frequency of the alien attacks, as well as the familiar aliens themselves, raises Max's suspicions, and he heads to Mount Rushmore, where he finds the Null Void Projector—a weapon that can trap things in, or release them from, an alternate dimension—missing. Phil has been abusing it to scam various hotel owners into paying him to remove the aliens that he sets free.

During a trip to Yellowstone National Park, Ben discovers a new alien on the Omnitrix, Cannonbolt, an armadillo alien. At the same time, a meteor crashes nearby unleashing a giant, tick-like alien called the Great One that intends to devour the planet. On top of that, it has its very own worshipers, who intend to make sure it completes its task. Ben easily defeats the worshippers, but the Great One turns out to be impervious to the original ten aliens. Ben quickly discovers that Cannonbolt is impervious from any attack when rolled into an armored ball and penetrates the Great One's armor in that form, killing the alien from the inside.

In San Francisco, Ben discovers that look-alikes of his aliens are committing crimes around the city. Ben encounters the imposter and discovers that it was really Kevin; their last battle has permanently given Kevin the ability to transform into the various aliens of the Omnitrix. Kevin leaves Ben to pay for his own crimes performed as Omnitrix aliens, bringing Ben into direct conflict with the ruthless Lt. Steel of the government's Special Alien Capture Team. Four Arms confronts Kevin atop the Golden Gate Bridge, where Kevin's rage forces one final transformation: a fusion of all of the Omnitrix aliens without the ability to revert to human form.

When Ben wakes up one morning, he finds the Omnitrix missing from his arm. Weirder still is the fact that Gwen and Grandpa Max have no idea what he's talking about when he asks about it. Ben soon discovers that he's reliving the very first day of summer, the same day that Ben found the Omnitrix to begin with, but in an alternate reality. At the campsite, Ben tries to find the Omnitrix as it crashes to Earth, only to find out that it has already been found by Gwen. Gwen quickly adjusts to the Omnitrix's powers but she uses the Omnitrix much more than required and when Vilgax attacks, she finds the Omnitrix is discharged and will take some time before it becomes usable.

While Diamondhead battles the still-mutated Kevin, who had rendered Gwen and Max unconscious, a teleportation beam takes Diamondhead and Kevin to a huge ship called the Megacruiser, led by droid Slix Vigma, where life or death gladiator matches are regularly held between slaves captured from different alien races. Vigma makes Ben and Kevin a team, bonding them with shackles that transfer pain from one to the other, so they battle another captive, Technorg. After the fight, Kevin traps Ben with the intent to kill, revealing that he still bears a grudge, but Ben transforms into Cannonbolt and knocks him out. Technorg abides by a code of honor and saves Ben, sending him back to Earth, while Kevin is left aboard the Megacruiser with Technorg.

When a pair of bounty hunters (Six-Six and Vulkanus) plan to use raw minerals from earth to build a devastatingly powerful bomb, Ben joins a group of alien super heroes, the Galactic Enforcers, in order to stop them. However, all is not well with the new group, as a small gift of Ben's chocolate is all that's needed to weaken the group's leader, Ultimos, which causes his second, Synaptak, to take the lead in order to try showing Ben up. However, the Enforcers tactics involving 'commanding presence' backfire on them, and nearly getting group member Tini hurt in the process. However, after Ben goads Synaptak into rescuing Tini from a landslide, Ben and the Enforcers put aside their differences to finally arrest the bounty hunters.

Distracted by Ben and Gwen quarreling, Max almost hits a young camper named Gilbert on the road. They take the boy back to his camp, Camp Opinicon, only to find no one there. As they investigate the premises, they find two more children, twins named Andy and Mandy, who are hiding from something that caused the camp to become deserted. Max is captured by tendrils while he investigates, prompting Ben and Gwen to split up. While Gwen leads the campers to safety from fungal mutants, Ben attempts two failed rescue missions, getting captured on the second. In trying to escape, Ben unlocks a new alien form, a plant-like alien named Wildvine.

Max's Plumber equipment detects that an ancient mask had been unearthed. This quickly triggers a change in Max's attitude; he claims that this artifact would lead to the most powerful weapon ever designed, and that he should retrieve it before it falls into the wrong hands. Max immediately becomes more impatient, worse-tempered, and far stricter. Upon retrieving the mask, the Tennysons come into conflict with The Organization, now called the Forever Knights, who want to find the weapon themselves. The Tennysons end up with the mask after a struggle and use it to find the ultimate weapon, the Sword of Ekchuah, inside of a Mayan pyramid.

Gwen dons her Lucky Girl costume again upon finding the mystical Keystone of Bezel at a convention in Las Vegas. Rather than extremely good luck, the Keystone greatly strengthens all of Gwen's natural abilities to superhuman levels tenfold and granting her superhuman agility, enhanced reflexes, and durability. At the same time, Hex has been busted out of prison by his niece, Charmcaster, and seeks to use the keystone to restore the destroyed charms. Charmcaster tricks Gwen into trusting her so that she could easily take the Keystone and give it to Hex.

The family ride a jet belonging to Grandpa Max's old friend, Donovan Grand Smith, who owns an underwater resort. At the entrance, they receive a warm welcome from Donovan himself, though they also meet with his grandson, Edwin, who doesn't seem to be excited about their guests. When Edwin, Ben, and Gwen enter the Undersea Manta Ray, a giant submarine, they encounter strange aliens that threaten to destroy the whole resort. While the kids find a way to cooperate with each other to find the source, the aliens want to retrieve as it turns out that it was a piece of their technology.

Ben has been having strange nightmares about Ghostfreak. During a tour of an academy school Gwen wishes to attend, Ben sees and hears Ghostfreak everywhere. When Frightwig, Acid Breath, and Thumbskull show up, Ben activates his Omnitrix; however, it transforms him into Ghostfreak. After a vicious battle, during which Ben is clearly no longer in control, Ghostfreak escapes from the Omnitrix. Ghostfreak removes his second layer of skin in order to possess Ben, revealing a horrifying creature underneath, and he scares the circus trio into working for him as he schemes to possess Ben and gain control of the Omnitrix.

When Ben tries to take apart the Omnitrix to see how it works, he ends up breaking off its face and causing weird combinations of his alien forms when he transforms. Additionally, the broken piece begins mutating the smaller creatures it comes into contact with. Meanwhile, Dr. Animo escapes from prison and, during a battle with Ben, finds the broken piece of the Omnitrix. Using it, he is able to complete his large-scale Transmodulator, giving him the power to mutate the entire planet in a single shot.

Ben accidentally figures out the master-control of the Omnitrix, allowing him to become any alien just by thinking about it at will. Elsewhere, Kevin had assumed control of the Megacruiser and he locates and revives Vilgax, who realizes the nature of Kevin's mutation and decides that he may be of use. Kevin and Vilgax locate Ben and fight until Max attempts to trap the enemies in the Null Void dimension; however, Ben gets pulled in as well and ends up continuing his battle in another realm, so Gwen enters the Null Void in order to retrieve Ben.

As Ben and Gwen are planning Max's birthday, a mysterious stranger appears out of nowhere and kidnaps her, so Ben follows her into a strange portal as XLR8. When the dust settles, Ben suddenly realizes he is twenty years later in the future, where humans and aliens live peacefully. Ben then learns that Gwen's captor is her own thirty-year-old future self, and a master sorceress to boot. Gwendolyn reveals that the current Ben, called Ben 10,000, is now a world-renowned hero with ten thousand different alien forms at his disposal. But, upon meeting his future self, Ben realizes that the future Ben is all business and just can't relax and have fun, not even for his own family.

While visiting a mega-mall, Ben and Gwen watch a hypnotist perform. Gwen volunteers Ben as a test subject, and the host, Sublimino, successfully hypnotizes him. When asked to act like an alien, Ben naturally turns to the Omnitrix and almost changes in front of the audience. Even though he is stopped by Gwen, the trouble doesn't end there. Sublimino is able to use those he hypnotizes to commit crimes in their dream state, and the alien-equipped Ben proves to be the perfect accomplice.

While Ben and family are visiting Salem, Massachusetts, Charmcaster attacks in an attempt to magically switch bodies with Ben to attain the great powers of the Omnitrix but Gwen interferes, causing Charmcaster to switch with her instead. Gwen is punched out by Charmcaster before she can explain anything, and is then arrested and sent to juvie. Charmcaster stays with the unaware Ben and Max and tries to cook up another body-transference spell but Gwen escapes from juvie and returns, convincing Ben of the truth before Charmcaster tries again. However, Charmcaster manages to swap their bodies once more, ending with Charmcaster in her true body while Gwen and Ben have switched.

Ben, Grandpa Max, and Gwen come upon a bizarre Christmas village run by a Christmas-obsessed man (Mr. Jingles) who thinks Grandpa Max is Santa Claus and proceeds to trap him. As Ben and Gwen explore, they learn about a strange curse on the village from one of its few disloyal elves, including one, who happens to be the son of the Christmas-obsessed man. The village was frozen at Christmas, in the 1930s. But when Ben delivers all the gifts that had been made, time catches up to the village instantly.

During a visit to New Mexico, Ben falls in love with a Native American girl named Kai Green while a wolf-like creature appears in a flash of purple lightning. Kai's grandfather, Wes, an old friend of Max, believes it to be a Yenaldooshi, or Navajo werewolf. Wildvine fights the creature, but it bites Wildvine's root just before Ben returns to normal. It nearly kills Ben as a human, but he is spared when the wolf accidentally scratches the Omnitrix rather than Ben himself. Afterwards, Ben begins transforming into a werewolf himself, presumably an effect of the bite. However, the group discover that the werewolf is an alien. By scratching the Omnitrix, it added its own DNA to the Omnitrix, which was gradually shifting Ben into Blitzwolfer.

Ben and Gwen are playing the Sumo Slammer video game and Gwen is beating Ben at it. Ben turns into Upgrade and merges with the computer so he can lower Gwen's score. As Gwen tries to get Ben out, lightning hits the van and zaps them both into the game. They realize that all of the aliens in the Omnitrix are unavailable and they have to collect tokens in order to activate certain ones. They progress through the levels in order to get the Upgrade token and allow them to leave the game, but the villain of the game hears them and wants to use the Upgrade token to leave the game and take over the real world.

When a television show called Super Alien Hero Buddy Adventures shows up, Ben gets angry and demands credit since it stars corny cartoon versions of Fourarms, Heatblast, and Wildmutt. Furthermore, it has replaced his favorite show, Kangaroo Commando. It just so happens Ben and Gwen are visiting Planetary Studios at the time, so he tries to confront the producer about it. Meanwhile, strange accidents begin occurring around the actor who plays The Commando, conveniently allowing the actor to save the day. The Commando suspects that the artist producing the cartoon, Tim Dean, is responsible, but Gwen suspects foul play on the Commando's part.

In order to teach Ben and Gwen the value of hard work, Grandpa Max takes them to a farm. However, Todd, a son of a farmhand named Joan Maple-wood tells Ben and Gwen of a mysterious mummy that had recently arrived in a flash of purple lightning that sparks their curiosity. The two of them find it digging for a strange stone, but it attacks them as soon as they see it. XLR8 fights it to no avail, but the alien mummy flees in the confusion. Max discovers that the strange rock is an unstable energized mineral called Corrodium, which causes severe mutation in earthly organisms if exposed.

Ben goes to see his favorite Little League team. Unfortunately, who should be on his team but his rivals, JT and Cash. He discovers that their opponents, the Squires, are robots. He cheats for his own team, but it works against them when the robots try to kidnap people on the team who appeared to be experts due to Ben's help. While attempting a rescue, Ben discovers that the robots plans are to replace the President of the United States, who had also been watching the game. After the Tennysons save the President and leave, Enoch appears, revealing the plan to be his own. He vows that the Tennysons will pay with their lives.

Grandpa Max takes Gwen and Ben to a music festival in Chicago to see his favorite old time band, Shag Carpeting, but the event is interrupted by a weather-controlling robot called S.A.M. Ben uses Four Arms to send shockwaves to the robot, eventually destroying him.

A shuttle launch at NASA is interrupted by a purple lightning storm, which attracts the attention of the Tennysons, who hope to discover the origin of the alien werewolf and mummy. While at NASA, Ben runs into an ill-tempered scientist by the name of Dr. Viktor. Surveillance tapes associate him with the purple lightning storm, and he is quickly shown to be in cahoots with the two creatures. The Tennysons encounter the creatures again, in addition to Doctor Viktor in his true form and, following a losing battle, they split up: Max and Gwen board the space shuttle that Viktor launches, and Ben as XLR8 follows Vicktor, who revives his master and commander, who to Ben's horror is revealed to be Ghostfreak.

Ben transforms into Grey Matter to escape from Ghostfreak and Viktor. He is able to discern Ghostfreak's plan from a computer terminal: using the corrodium to amplify the power source of the orbiting space station, in conjunction with the device the alien werewolf built in New Mexico, Ghostfreak is intent on covering the daylight side of the Earth in a corrodium shield. This will not only mutate Earth's population, but it will also block out the sun, giving Ghostfreak a world of eternal darkness to rule over. Ben uses Upgrade to create a makeshift rocket to get to the space station, which Vicktor clings to so that he might also get to the station, while Max and Gwen fight the mummy aboard the space center and attempt to thwart Ghostfreak's plan from there.

A female alien named Xylene locates the Omnitrix and attacks Ben, under the impression that he had stolen it but when Max comes to defend, the two recognize each other as old comrades and sweethearts. Xylene and Max reminisce later that night, which indicates they had been in quite a romantic relationship during Max's early Plumber days. Xylene reveals that she was the commander of the ship bringing the Omnitrix to Earth when Vilgax attacked it, and that she had intended to send it to Max; Ben received the Omnitrix by accident. One of Vilgax's remaining drones attacks and captures Max, so Ben and Xylene reluctantly team up to save him Xylene unlocks Upchuck to defeat the drone.

Ben seems to be having a perfect day but when another Gwen and Grandpa Max show up, he discovers that Enoch and the Forever Knights have trapped him in a dream world while they attempt to remove the Omnitrix from his wrist. Revealed, Enoch turns the dream into a nightmare, which is Ben's school. After managing to take control of the dream and escape, Ben traps Enoch in his own dream world. Once the Tennysons leave, another Forever Knight, the Forever King, decides to leave Enoch in the machine as punishment for his past failures.

Dr. Animo has just escaped from prison with the help of a mutated seagull, plotting to get revenge on Ben once again, who is at the beach with Gwen and Max. Ben is being impulsive as no one will play with him, until he is confronted by Animo's seagull. During the fight, Ben discovers a new alien on the Omnitrix, Ditto, who has the power to multiply at will. Ben manages to drive of the seagull and enjoys playing as his multiple Ditto copies. However, one of Ben's Ditto clones is captured by Animo himself, in hopes of exploiting his alien DNA for his own evil purposes.

Growing weak with old age, Hex is seeking out something to make him stay young. At the same time, Max is having difficulties with his aging body, so he decides to impress his grand-kids at a fair to show them he's not as elderly as he seems. At the dunking game Max challenged them to, he and Ben both get splashed, unaware that the water is from the Fountain of Youth. Max regresses into a ten-year-old while Ben becomes a four-year-old. Hex manages to force the booth's owner, Hector, into revealing the location of the fountain as he is its guardian, having been charged to do so by Juan Ponce de León 400 years previously.

Ben, Gwen, and Grandpa Max attend a family wedding for Max's nephew Joel and his bride-to-be, Camille. Before the day of the wedding, Ben interrupts a mud alien's attempt to sabotage the wedding. Ben defeats the sludge alien as Cannonbolt but finds the groom's parents pointing rifles at him soon after. He escapes with Gwen's help, and Max explains that the groom's side of the family are all Plumbers, while the bride's side are all mud-like aliens, called Sludge-puppies, which the Plumbers were sworn enemies with until Joel and Camille met and forged a romance, which makes the wedding a truce. However, during a dinner time with the families, they are confronted by Camille's ex-boyfriend.

While traveling through a desert, the Tennysons encounter a group of modern-day pirates called the Road Crew attempting to hijack the deluxe RV of Laurence Wainwright. After stopping the Road Crew, the family makes a pit stop and Ben and Gwen start to complain about how the Rust Bucket doesn't work right and isn't nearly as luxurious as Laurence's RV. Shortly afterwards the Road Crew returns and steals the Rust Bucket. While Grandpa Max tries desperately to track down the Rust Bucket, the Road Crew give it a makeover for use in their plans.

After seemingly damaging Gwen's new laptop, Ben enters a mutant wrestling competition as Four Arms to earn some money to replace it, becoming an instant celebrity. During the tournament, he fights a pair of mutant brothers who owe a mob boss a large sum of money in order to save their farm. They entered the competition in order to pay off their debt, which Ben doesn't learn about until after defeating them. After learning the truth, Ben goes with them to save their mother, who is being held by the gang as collateral damage.

Thirty two years later in a possible future, Ben's son Kenny is celebrating his tenth birthday, and to commemorate the occasion Ben gives him an Omnitrix of his very own. Kenny soon befriends a boy named Devlin, and the same night Ben's old foe Kevin 11 attacks their home looking for the Null Void chamber. Unable to locate the chamber, he retreats. Kenny becomes angry at his father for not telling him or letting him fight Kevin and endeavors to find the chamber with Devlin. When they find it, Devlin mutates into Kevin's mutant form revealing he was the real attacker from the previous night, and activates the chamber, releasing the real Kevin, who is Devlin's father and reveals he absorbed more alien abilities while imprisoned and mutates into a new form, Kevin 11,000.

The Tennysons pick up the grandson of another Plumber named Cooper, who is hitching a ride home with them. Meanwhile, a Plumber base at Fort Knox is robbed by the Circus Freaks and Sublimino. By the time the Tennysons find out, they are too late to help. They soon learn of a second robbery, this one run by Rojo (having gained a new cybernetic suit), Animo, Clancy (mutated into an insect), and Charmcaster. Max discovers that they are searching for the keys to the Sub Energy, an extremely potent sub-atomic power source given to the Plumbers by an alien race. They lose the keys to the villains, and attempt to rout them at the Mount Rushmore base, where the Sub Energy is stored. However, they find that the Forever King, joined by a subordinate and the villains that raided the earlier bases, has beaten them to it.

Ben, Gwen, and Max, along with Cooper, use the Plumbers' Mount Rushmore installation to mount a final stand against the Forever King's forces. Max discovers that the Forever King was once a plumber named Driscoll who was kicked out after hoarding alien technology. Despite their best efforts, they are unable to keep Driscoll from obtaining the Sub-Energy. Driscoll uses the sub-energy to tremendously increase his armored suit and battles Ben, who is able to use Upchuck to digest the power source and destroy it safely.

Ben returns home after the summer vacation ends and is told by Max that he must keep the Omnitrix a secret. Ben gets the chance to use the Omnitrix when Vilgax attacks, yet again looking to take the device from Ben. All four Tennysons (with the help of Ben's father Carl) fight off Vilgax's drones running amok in the city. When Vilgax appears again, easily fending off Ben, Ben's father suggests leading him into the underground gas line, which they ignite to incinerate the villain. Ben's secret is revealed to the public during the affair, and Gwen ends up transferring to his school. Just when it seems like everything is quiet, Dr. Animo shows up with a cadre of mutated animals, which Ben and Gwen get ready to fight.

After setting aside the Omnitrix some years ago, 15-year-old Ben Tennyson discovers his Grandpa Max has disappeared. Inside Max's, Ben finds RV a Holo-viewer with a recording from Max and he asks his cousin Gwen for advice as they meet Magister Labrid, an agent of the Plumbers and Max's partner in a case he was working on. They go to a train station where an arms trade between the Forever Knights and the DNAliens, brokered by Kevin Levin. Ben tries to dial in his alien on his Omnitrix, but it reboots and recalibrates into a thin watch with a color scheme of green and black, giving him access to 10 new aliens. The DNAliens get away, the Forever Knights escape with one of the weapons crates, and Kevin is captured. The Plumber asks Kevin for help in finding the Knights' hideout.

The group runs into an army of Forever Knights. In the confrontation Magister Labrid is killed when he saves Kevin's life, and Kevin joins Ben and Gwen on their search for Max to repay his debt. Gwen is able to trace a leftover Laser Lance back to its original owners, and they soon find a secret underground base infested with DNAliens. Sneaking in, the find that Max isn't there anymore, and on their way out, they see that the Highbreed in charge of the ship.

The authorities of a local town named Grover's Mill arrest a half-human, half-Pyronite boy named Alan Albright for arson and criminal damage. He is wearing a Plumber's badge, which leads Ben, Kevin and Gwen to Alan, thinking Alan's badge is Max's. Elsewhere, Alan uses his pyrokinetic/thermokinetic abilities to escape the officers, and the resulting damage to a building leads the team to believe that Alan may have hurt Grandpa Max. Ben soon discovers that the DNAliens are responsible for the damage, having built a huge, needle-like weather machine in the corn fields.

Kevin meets with an old friend named Argit, who claims he knows the location of a particular piece of alien tech Kevin is looking for. Needing something to bargain with, Kevin steals Max's RV, the Rustbucket, but Argit double crosses Kevin and steals the RV for himself, after seeing the huge amount of Plumber's tech and weapons inside it. The team follows Argit with a tracking device that Kevin hid on the Rustbucket's undercarriage and stops Argit, but Kevin storms away to seek out Vulkanus, who is in possession of the alien device. Kevin tries to make a deal with Vulkanus, but the later forces Kevin absorb a rare alien crystal called Taedenite, planning to use him as a living gem mine.

Ben, Gwen, and Kevin set out on their mission to locate other Plumbers' children and they encounter Michael Morningstar. Since he has all the Plumber's gear of his late father, as well as the fact that he seems to have been helping his city using his energy-controlling abilities, Ben and Gwen are quick to trust him. Kevin, however, remains suspicious. Finding a group of zombified school girls at a power plant, the team engages in a short battle, and Michael accidentally lets them escape. Kevin later discovers Michael is making the zombies, draining the schoolgirls of their vital life-force energy and then commanding them to collect more strength for him. Gwen sees through Michael's facade and takes back her energy for herself. Kevin crushes Michael's Plumber badge after Ben's team defeats him, telling him he doesn't deserve it.

Gwen's older brother Ken is missing, and she asks for Ben and Kevin's help to find him. The gang stumbles upon a Highbreed base in a small town called Santa Mira that manufactures Xenocytes, headcrab-like parasites that mutate humans into DNAliens. Ken has been infected by one of the Xenocytes, but Ben is able to remove it with the help of the Omnitrix. With Ken in tow, the gang finds Grandpa Max inside the base. While they help him in his mission, Max sets about destroying the factory while searching for the egg-laying machine. Upon their return, the gang finds Max locked in battle with a Highbreed Commander. In an act of self-sacrifice, Max uses an unfocused Null Void warp projector to destroy the Highbreed base, leaving his fate unknown.

Gwen tells Ben to ask Julie to go on a date with him to a local boardwalk amusement park, the Pier. After Ben attempts to ask her out, Julie agrees. Elsewhere, out in the forest, a small dog-like Galvanic Mechamorph seeps out of a crashed spaceship. Seeking a Plumber's badge signature, the Mechamorph soon finds Ben and starts taking control of the rides to get Ben's attention. After a few failed attempts, the alien then uses a ride to kidnap Julie. In the process, Julie finds out about the Omnitrix. The two follow the Mechamorph to the crash site. The Galvanic Mechamorph, accidentally given the name Ship, is reunited with his owner, Baz-El, another Galvanic Mechamorph who looks more human. He leaves Ben and Julie in peace.

While Ben, Gwen, and Kevin are taking a break at Max's favorite fishing spot, they see a mysterious cloaked woman leave a flower at the base of Max's favorite tree. When the team tries to meet her, she disappears. They decide to stake out the area for a while until the woman shows up again. The woman shows up, and is able to beat both Ben and Kevin in battle with ease. However, when she sees Gwen use her powers, she is amazed. As it turns out, Gwen's magical powers are in fact inherited from the strange woman, who turns out to be Ben and Gwen's long-lost paternal grandmother, Verdona, who is an immensely powerful energy being called an Anodite from the planet Anodyne. She attempts to convince Gwen to break out of her human body and embrace her full Anodite power, but Gwen refuses, even after a long fight. Verdona leaves, but promises it won't be the last time she asks her.

After the team faces off against a Techadon robot, Kevin grabs the severed hand of the robot and places it in his trunk. At night, Ben's childhood bullies J.T. and Cash Murray see Kevin's car outside a restaurant, and decide to wreck it. They push it down a hill, smashing the trunk open. They look inside and grab the Techadon gauntlet before the car's alarm attracts Kevin. Back at their hangout, Cash puts the gauntlet on, planning on using its built-in laser blaster to destroy Ben once and for all and repair their reputation but the full robot armor begins to reform around Cash's body. In doing so, the arm messes with Cash's mind, making him more hostile than usual. Ben fights Cash, and J.T. attempts to reason with him. After remembering his friendship with J.T., Cash's willpower overrides the robot arm, and it gradually reduces in size to the point where Cash can take it off. J.T. and Cash walk away with a newfound respect for Ben.

The team gets word of a strange creature roaming around an abandoned desert town named Los Soledad outside of Bellwood. The creature seems to be aging everything it touches at an accelerated rate. While Ben, Gwen, and Kevin investigate, they see a strange man who seems to be able to disappear at will. After trying to fight him, the team soon formally meet the man who they name Professor Paradox (as he forgot his original name after spending 100,000 years detached from time and space), a scientist from the 1950s who was sucked into the event horizon of his time-travel experiment. Displaced from time and space, Paradox is able to move through time at will. However, the same mistake that rendered him ageless created the creature they seek. After analyzing its movements, they come to the conclusion that its movement is like that of a man desperately attempting to find his way out of a strange town. They realize that it was Paradox's assistant, Hugo, and attempt to travel back in time to prevent him from turning into the creature. As they open a portal and push Hugo away from it, Paradox gets leverage from gumballs, which he claims are unaffected by time, and they are able to place Hugo back into his proper time. Back in the present, the team sees Hugo, now normally aged, and Paradox exchanges pleasantries with him before he departs. Kevin discovers that Paradox fixed his car in the process. Inside, he discovers a note saying that if it were to come into contact with anything from 1976, it would explode like antimatter.

Kevin has arranged a meeting for Ben with the Forever Knights, who need help in slaying a dragon they have kept captive underneath their castle for 1,000 years. After teaming up with the Knights' mightiest warrior, Sir Connor, in a failed attempt to destroy the dragon, Ben notices that the dragon appears to be trying to communicate. The team leaves the Knights behind and tracks the dragon to a warehouse where its spaceship is being held. Ben as Spidermonkey fits the dragon with a universal translator so it can speak, and it reveals that he is an alien mapmaker, but was captured by the Forever Knights. Ben helps the dragon find its spaceship, and it departs in peace. He then starts to question the motives of the Forever Knights.

A pair of rogue half-human plumbers' kids, a female human-Kineceleran named Helen Wheels, and a male human-Tetramand named Manny Armstrong, have been attacking stray DNAliens and all other aliens they can find, and sucking them into a Null Void projector, believing it to have vaporized them. Believing that the team is DNAliens in disguise, they kidnap Kevin, intending to use him as bait for Gwen and Ben. After his rescue, the two sides work things out. After looking at a database of the aliens they captured and put into the Null Void, Ben realizes that some of them may have been Plumbers' kids. To make things right, the duo set out into the Null Void to rescue those they wrongfully imprisoned.

The Incursean Emperor Milleous's daughter Attea is kidnapped by the bounty hunter Sevenseven. Unless she is returned, Milleous plans to destroy the Earth. The Emperor's majordomo, Raff, seeks out Kevin to help on the search. Using Gwen's powers to track her, they teleport to a nearby dam to rescue her. When the dam is broken , Ben uses the untested Alien X to try to fix it. The task proves simple thanks to Alien X's vastly strong reality-warping capabilities, but Attea is yet again captured by Sevenseven and Ben finds himself locked inside Alien X in endless debate with the alien's other two personalities, Bellicus and Serena, unable to move or transform back without their consent. Meanwhile, Kevin and Gwen struggle against the Incurean forces attacking them at all sides. Eventually, Ben is able to convince Serena to trasform him into Swampfire, and makes quick work of the enemies. The team completes the job successfully, and Milleous informs them that Earth will be spared.

After a Plumber setup to find out if the team has been masquerading as Plumbers, Ben, Gwen and Kevin are forbidden to fight against the Highbreed threat by Plumbers Magister Prior Gilhil. Ghilhil has doubts the Highbreed are even as much of a threat as they claim. Elsewhere, a mysterious powerful new enemy 'employs' a Highbreed to attack the team. Having also tipped off Gilhil, all three side are captured by the team's old enemy, Michael Morningstar, now calling himself Darkstar.

After an accident with a teleporter pod, Ben and a Highbreed officer named Reinrassic III are stranded on a desert planet called Turrawuste. The pair are forced to work together to fend off the dangerous predators on the planet while making their way to the routing station, much to Reinrassic's chagrin. As they make their way across the desert, the two save each other from danger several times from the violent native wildlife, even risking their own lives to do so.

A Galvan (Grey Matter's race) named Albedo builds his own Omnitrix and is permanently stuck in Ben's human form (since wearing the Omnitrix, Ben's DNA has become a default in the Omnitrix). Desperate to find Ben, Albedo resorts to destroying DNAlien hives and Forever Knight castles, demanding information on the teenage Omnitrix wearer. When Gwen and Kevin hear rumors of Ben causing all that damage without them, they're naturally suspicious of the real Ben, who has been studying for a physics test the entire time.

Gwen asks Kevin to take her to her school's dance, forcing a clueless Kevin to seek advice from Ben. However, Ben has his own problems as Big Chill is overriding the Omnitrix, and taking over his body with each transformation.

After trying to test a broken teleporter pod, the team decide to enlist the help of Cooper Daniels, the young boy who had helped the Tennysons in the past. Upon reaching his home, they discover a video of his capture by the DNAliens. They track him down to the abandoned military base Los Soledad, where Paradox built his time machine. They discover that the Highbreed have erected a cloaking field, built by Cooper over the area, concealing a huge, mysterious arch-like device.

Forever Knights' scientist Dr. Joseph Chadwick sends Sir Morton to kidnap Ship so that the Forever Knights can use him to mass-produce a fleet of interstellar spacecraft with which to attack the homeworld of the alien dragon that escaped them. Morton attacks Ship, capturing the small alien. Ben arrives too late, and the team sets out to find the Knights. Assuming that the Knights have something to do with a medieval-themed track of houses, the team, joined by Julie, attempt to sneak into the main house to rescue Ship.

While fighting one of the Highbreed, Ben's parents catch him transforming into Swampfire. Seeing as he comes home with a black eye, they forbid him from using the Omnitrix ever again for fear of him getting hurt. With Gwen and Kevin on the trail of a Highbreed plot, Ben tries to sneak out of the house as Echo Echo. Once Ben's parents see that he disobeyed their orders, they ground him. His various attempts to aid his allies by phone and by computer only results in Ben being forced to tell his parents about Gwen helping him, resulting in her suffering the same fate as her cousin, and leaving Kevin alone to find out what the Highbreed are up to.

Helen and Manny use Gwen's powers to call on Ben's team to help deal with a dangerous foe in the Null Void: D'Void. Ben goes in alone, with Kevin and Gwen waiting on the other side to bring him back. Once inside, Ben is shocked to learn that D'Void is really his old enemy Dr. Animo, who has taken control of the Null Guardians and enslaved the inhabitants of the Null Void. Ben later encounters Grandpa Max, who was transported to the Null Void in Max Out and has been leading a resistance movement under the name of The Wrench.

The team rescues a young man named Tyler, who stole the Oscillator Key for the Highbreed's hyperspace gateway from Los Soledad. He crashed the truck and suffered memory loss as he escaped. After being almost captured by the DNAliens in a small town, the team saves him and are forced to race the DNAliens to track down the device, resulting in a battle. The team is victorious, but they discover that Tyler is actually a DNAlien, having managed to resist the Xenocyte controlling him, and only looked human through the use of an ID Mask.

An Arachnichimp (Spidermonkey's race), Simian, needs help in retrieving a crystal which is supposedly the symbol of the monarchy on his planet. The crystal is being kept in a base on the moon. Ben offers his help, but Kevin and Gwen are skeptical. In the midst of the battle, Ben discovers that Simian has been lying, and that the crystal is actually powering an intergalactic communications station. By stealing it, Simian will prevent Earth from calling for help against the upcoming Highbreed invasion.

A DNAlien mining operation under Los Soledad uncovers an alien spacecraft, from which a large alien creature is released. It wanders around the nearby town collecting random items, eventually attracting the attention of Ben, Gwen, and Kevin. After a short battle, they realize that the alien is in fact a baby girl. The alien perceives Gwen as an Anodite and hangs on her every word. Needing to return the baby to her parents, the team follows her back to her ship.

Paradox and Azmuth arrive on Earth to warn Ben of the approaching Highbreed fleet. Gwen and Kevin gather all the allies they've met (Alan, Cooper, Julie and Ship, as well as their enemy Darkstar) to counter the threat. Meanwhile, Azmuth reveals to Ben that the Omnitrix contains the DNA of every sentient species in the galaxy, over one million in total, and unlocks the Master Control so Ben can effectively combat the Highbreed.

The team has to get to the captain of the fleet, on the Highbreed head ship to stop the invasion. Ben, Gwen and Kevin quickly head to the captain of the fleet. The Highbreed commander and the team fight. The trio is then surrounded by a group of DNAliens, but are saved by Grandpa Max, Pierce, Helen and Manny plus one Null Guardian, who have regained control over the Null Void. Ben, Gwen, Kevin, Azmuth and Ship as a spaceship head to the Highbreed's home world to confront the Highbreed Supreme.

Vilgax begins by winning a Conqueror's Challenge and drains the powers of the champion who he defeats. He then heads to Earth in an attempt to get revenge on Ben. Meanwhile, Ben is seen acting more arrogant as he receives another medal for saving the universe, and is shown to have received many of them. He shows up late to a mission and Gwen and Kevin are angry at him. Psyphon shows up on Earth and summons Vilgax, who defeats Max and the other Plumbers. Kevin attempts to hack the Omnitrix despite a warning from Azmuth but is transformed into a combination of different metals and some of Ben's aliens escape the Omnitrix.

Ben begins by recapturing the lost aliens of Chromastone, Spidermonkey, and Goop before taking on Vilgax. However, despite trying to use Jetray, Big Chill, and Humongusaur he is unable to defeat Vilgax. Gwen and Keving show up with Way Big, who Ben scans and attempts to transform into, but he becomes Chromastone instead. Vilgax smashes Chromastone and Psyphon picks up the Omnitrix, but then Ben reappears as Diamondhead and defeats Vilgax, saving the Earth.

Ben, Gwen, and Kevin discover that Vulkanus is planning to drill to the Earth's center.

An alien asks Ben to help locate his missing best friend.

Ben and the team travel to an alien planet to resolve a conflict between the inhabitants. Kevin finds the Argit has been selling the weapons from one side to the other after painting them a different color. A temporary truce occurs, but as Ben attempts to shake hands with the leaders of each side, one side takes offense and the war restarts. Then Ben kidnaps the leaders of each side to attempt to force another truce, but they escape after blinding Ben with a flashlight. Ben transforms into Way Big and accidentally breaks a statue of the planet's former leader. With both sides fighting angry at Ben, he flees the planet.

Ben and Kevin try to thwart repo-men sent to return Ship to his maker and appeal to a judge to rescind his ruling.

A bounty hunter who's after the Omnitrix sends Ben to the Null Void, but his left hand remains on Earth.

Ben and the team have to thwart a Highbreed failsafe, which gets accidentally set off.

Charmcaster returns and gets Kevin to help her to defeat Gwen.

Vilgax asks for Ben's help to take down Zs'Skayr who has taken over his planet.

Kevin teams up with Darkstar to retrieve an artifact that could cure both of them.

Ben and the gang battle an alien's toy which proves to be very dangerous.

The Omnitrix malfunctions, turning Ben into a ruthless and aggressive alien while on an intergalactic peace mission.

Ben and the gang get transported by the Omnitrix to a strange new planet where they encounter Vilgax.

Gwen goes back in time to stop the Omnitrix experiment from ever happening while causing disasters in the present time.

A sick Ben is happy to see an old friend Tetrax but finds out he has plans of his own.

The Plumbers' Helpers travel to a Plumber station to rescue Max from an insane, rampaging Ben.

Kevin decides to settle old scores with an escaped con.

Vilgax and Albedo return and team up to kidnap Kevin and Gwen so that they can take down Ben.

Ben gives up the Omnitrix and overcomes seemingly impossible odds to defeat Vilgax, who has betrayed Albedo.

Ben's secret identity is revealed to the entire world, and he is now a superhero loved everywhere by kids and teenagers, but distrusted by many adults. Kevin and Gwen find out who revealed Ben's secret and where he lives, and the three go to "pay him a visit". The informant turns out to be a young boy named Jimmy Jones, who has followed Ben's exploits ever since he was ten-years old. With Jimmy's help, Ben and company discover a series of alien attacks in Florida. The unknown alien steals a nuclear device from a prototype interstellar rocket. The group follow the alien to its hideout and defeat it, learning that the alien is from another galaxy, having been kidnapped by a being named Aggregor.

Julie is playing her first big game, while the Forever Knights are trying to break into a museum. Ben also wants to go see the opening of a new Sumo Slammers movie. To deal with his dilemma, he transforms into Echo Echo and then changes back to human, creating three copies of himself with differing personalities. The arrogant Ben gets sent off to watch Julie's game, the kind Ben goes to help Kevin with the Forever Knights, and the rational Ben goes to watch the movie.

After Ben's secret identity is revealed, a bunch of his old enemies start attacking his family as a method of revenge.

Ben is approached by a video game producer in order to make a Ben 10 video game. Unfortunately, this producer is actually working for Will Harangue, who intends to create a robot to destroy Ben. The producer has all of Ben's aliens scanned, in order to have the robot learn their moves. The robot begins to attack, with a climactic showdown happening on the National Wall in Washington, D.C.

Ben defeats an alien who was rampaging through Bellwood. The alien, named Galapagus, chronicles how he was kidnapped from his home world by Aggregor. He explains how he met five other aliens, and they escaped him to end up crash landing on Earth. Ben mentions how they already found Bivalvan, and promises to make sure all the aliens are returned home.

A strange alien is offering big money (over $1 million) to someone who can open a safe (which is really a containment suit). That alien is revealed to be P'andor, who wants to be free of his suit. Eventually, Kevin accidentally releases P'andor in his radioactive form, whom Ben, Gwen, and Kevin have to stop.

If the castles Argit goes to refuse to let him rule their castles, he will use his new friend Andreas to destroy the castle. Andreas is also one of Aggregor's victims. Jetray then scans Andreas' DNA and gains a new form and transforms back into Ben. Argit gives Kevin money as payment for the money he owes him. Kevin then says that he loves money more than anything else in the world and Gwen gets mad at him for the remainder of the episode. Argit tells Andreas that Ben and his team are friends, but then a Forever Knight intelligence officer named Sir Dagonet comes in and turns Argit's Forever Knight garrison against Ben and his friends.

As Ben laments that things can't get worse, Aggregor shows up to recapture Ra'ad. The gang try to fight Aggregor, but he proves to be too strong for them. The Ultimatrix finally lets Ben transform, but unfortunately, all that he can transform into is an Amperi. With no choice, Ben transforms into AmpFibian and fights Aggregor.

He then kidnaps Julie, who was shown taking her anger over Jennifer out on the tennis courts. Nemesis then intercepts Jennifer's helicopter. When Ben calls Julie, Nemesis answers the call and tells Ben to "come and get me" if he wants to see her again.

Aggregor then begins to absorb energy and Kevin tries to reason with him, explaining that regularly absorbing energy caused him to go insane when he was a kid but Aggregor doesn't listen, claiming that it is a lie told by powerful Osmosians to control the weak Osmosians. Before Kevin can reason with him any further, Aggregor shoots Kevin with his spear. He then powers himself up and breaks the fabric of time.

Continued from the previous episode, Aggregor has absorbed the powers of Bivalvan, Galapagus, P'andor, Andreas, and Ra'ad, transforming him into Ultimate Aggregor. Ben transforms into Humungousaur and attacks Aggregor in a fight of rage and anger, seemingly pummeling him unconscious.

The Forever Knights discuss their plan for the weapon and Ben and the team come in to fight with Cash, J.T., and Oliver filming the scene. Kevin gets angry with them not helping and Psyphon comes in to destroy Cash and J.T., believing them to be the masterminds behind Ben Tennyson.

Underwater on Piscciss, a Magister Plumber named Pyke is searching for something. He finds a swimming object, which happens to be Ultimate Aggregor, who seems to defeat Magister Pyke.

The group is chasing Aggregor, who runs toward a door and shouts an incantation. The door glows symbols and opens to a world that looks like it is full of mana. Unfortunately, Four Arms wasn't strong enough to keep the door open, and it closes. After Four Arms transforms back into normal, Ben remembers the glowing symbols and writes them down, but Gwen is unable to pronounce the symbols correctly. She does know someone who can read them, and that person is Charmcaster.

Azmuth contacts Ben on the Ultimatrix and is not happy with him for failing to stop Aggregor from claiming three of the four pieces to the Map of Infinity. When Ben tells Azmuth that scolding him is not going to help, Azmuth agrees and then teleports Ben, Gwen, and Kevin to the Rust Bucket 3 in another galaxy, in which they find the Perplexahedron, a giant cube-like artificial planet. Moments later, they spot Aggregor approaching the planet.

With Ultimate Aggregor having all four pieces of the Map of Infinity, he'll be on his way to the Forge of Creation (Alien X's home planet). Professor Paradox helps Ben, Gwen and Kevin get to they need to go, but after Paradox left, Ben and the others ran into Ben's younger self. The four of them arrive at Alien X's home planet, where they battle Ultimate Aggregor and after Kevin gone insane in absorbing Ben's powers he defeated and absorbed Ultimate Aggregor. 10-year-old Ben goes back to where he belong from Professor Paradox.

Ben and Gwen arrive in Incarceon to tell Morgg that Ultimate Kevin is going to kill him. Morgg ignores their warning and has his robots take them to a room to stay in until a supply ship picks them up. Meanwhile, while the prisoners are still mining, Ultimate Kevin flashes back to the last time he was a prisoner. He was still Kevin 11 and got so angry, that he threatened to hurt all the other prisoners while Quince and his friend, Kwarrel watched him.

While taking a ride in Ben's car, Ben and Gwen discuss that Ultimate Kevin is still continuing his rampage on everyone that wronged him and that he needs to be taken care of. Just then, Ben accidentally runs over Argit, but he survives. Argit explains that he needs their help in order to hide from Ultimate Kevin.

Kevin has been absorbing the powers of the Plumbers' Helpers and Ben and Gwen had an argument whether they should kill or cure Kevin. Ben defeats Gwen and then battle the Forever Knights and Vulkanus to ask where are Kevin's whereabouts but neither of them gave Ben any answers. Gwen finds Ben and tells him that their old enemy Michael Morningstar can help find and cure Kevin.

Halfway to the end of the episode, Kevin is still rampaging . Ben and Gwen use Michael Morningstar, Julie, Ship and Cooper to help cure Kevin. Ben defeated Kevin and in Los Soledad Cooper use the power of the Entropy Pump to turn Kevin back to human and the powers of the Andromeda aliens and the Plumbers' Helpers return.

Ben, Gwen, and Kevin go out into the wilderness for a camping trip. During a car race between Ben and Kevin, a strange pod falls from space. While trying to open the pod, Gwen cuts her hand on it. The pod then opens to reveal a beautiful, dark green-eyed, blonde-haired girl. Gwen gives the girl some of her spare clothes and the girl reveals her name to be Eunice, though she doesn't remember anything else. As the camping trip continues, Eunice is revealed to have a strange connection to nature and Ben begins to develop romantic feelings for Eunice. Sunder then arrives on Earth on a mission to find Eunice.

Baz-El is on a distant planet where he is stealing some valuable gems from some temple statues. Later, the temple guardian worshippers attack Baz-El. Ship suddenly hears Baz-El's cries for help, and leaves Julie to help his old owner. Julie ask Ben for help to locate Ship, who left to help Baz-El. However, their break-up makes things difficult, but Gwen and Kevin agree to help Julie.

Zarcovia's soldiers has found the frozen body of Dr. Viktor. Prince Gyula and King Xarion want to see this weapon. Gyula wants to control Dr. Viktor to use him against rebels in their civil war, but Xarion tells him not to. King Xarion asks for help from Ben, Gwen, and Kevin and explains what Gyula is trying to accomplish. When they find Dr. Viktor's corpse, they are found by Gyula's soldiers. While fighting them, Dr. Viktor's ice block begins to melt and he breaks free; Gyula reveals that Dr. Viktor is under his control.

Jimmy Jones sees a meteor falling in a cave, where an alien plant attacks him. He tells Ben and his team about it, but only Ben believes him. They go in the cave but the plant isn't there. The next day, Jimmy sees Ben going into the cave and talking to the plant. He takes a photo of that, but the photo isn't good, so Gwen doesn't believe him. Later, Jimmy goes to the supermarket and Ben, as Humongousaur, attacks him. Jimmy takes his bicycle and runs, but Ben becomes Cannonbolt and hunts him down. Jimmy goes to Gwen and Kevin and they all go to the cave. In the entrance of the cave they catch Jimmy and they take him to the plant. Jimmy finds that Gwen, Kevin, and Ben are clones made by the plant.

The team goes to Gwen's house to find a solution to defeat Computron's minions from Dimension 12. When they go to Gwen's room, they find a dark-hair girl, who is Sunny, Gwen's naughty cousin. Gwen's mom insists they take Sunny with them. The team takes Sunny to the mission but they left her in Kevin's car. They go to fight the robots but Sunny follows them. She destroys the robots with ease and is very happy, but the team is looking at her strangely. Gwen tells her mother that Sunny is an Anodite, much to her surprise and disgust.

One year after the events of Ben 10: Alien Swarm, Victor Validus attacks Ben at night but when he defends himself, he finds a Nanochip that was believed to have been destroyed along with its Queen. Ben, Kevin and Gwen find Victor's daughter, Elena, to see what is going on.

An evil creature known as Lucubra released from another dimension has plans to enslave the human race for its master.

Ben, Gwen, and Kevin are summoned to Plumbers Academy to go under training. They create a good friendship with an alien named Tack and Ben dislikes the drill instructor, Magister Hulca, that is being targeted for revenge by a menacing Tetramand.

Gwen must juggle things around, in which she has to help Ben and Kevin recapture Dr. Animo, fill out invitations for her mother Natalie's family reunion, help Kevin get into school, finish exams, and go to her best friend Emily's piano performance. All in one day.

Following a visit from Paradox after a fight with Eon, Ben 10,000 from an alternate future arrives twenty years from the future to seek the aid of his sixteen-year-old past counterpart in tracking down Eon. It is revealed that Eon is actually an adult Ben from an alternate world, and that he wants to destroy all of the other Bens to become the one and only Ben Tennyson.

In flashbacks, Max tells the astounding story to Kevin, Gwen, and Ben of how he had met and fallen head-over-heels for Verdona when he was but seventeen years old in the 1960s.

The secrets of Area 51 are revealed to Ben Tennyson by Colonel Rozum after Old George infiltrates and destroys it, setting free the 775th prisoner.

Old George brings the Forever Knights in one group in order to vanquish every alien being on Earth.

Simian accidentally unleashes a Xenocyte Queen which orchestrates an invasion of the Arachnichimps' planet. When Eunice goes missing, Ben, Gwen, and Kevin end up helping Simian liberate the Arachnichimps' planet from a DNAlien version of the Arachnichimp Mizaru.

Techadon robots go after Ben on orders from Vulkanus to attain the Ultimatrix. Gwen and Kevin go across space to prevent Vulkanus from getting what he is after.

Julie joins a cult called the Flame Keepers' Circle. Unfortunately for her, Ben discovers that the Flame Keepers' Circle worships Vilgax; whom they mistake for the mighty Diagon because of his close squid-like resemblance.

Albedo profits from Ben's fame and creates a play about him with the help of three alien actors based on the aliens in Ben's Ultimatrix.

Elena and the nanochips return and impersonate Julie while the real Julie is at a tennis tournament overseas. Ben does not catch onto this until the very end when the real Julie returns and causes Elena to realize that she had never really loved and cared about the real Ben in the first place. Now knowing what true hatred is, Elena disappears with a promise to return.

The ultimate aliens inside Ben's Ultimatrix demand their freedom and end up sucking Ben into the Ultimatrix. While Gwen assumes her innermost Anodite form as her astral projection to enter the Ultimatrix to help Ben, Kevin travels to planet Galvan Prime to convince Azmuth to help.

The gang look into the Pacific Garbage Vortex when some people have gone missing. When they arrive, they find the missing people and two agents sent by Colonel Rozum while dealing with giant seagulls and a sentient Trash Monster.

Ma Vreedle plans to spawn an army of Pretty Boy Vreedle clones, which could dry up Earth's oceans.

Vilgax and the Flame Keepers' Circle fight against George and the Forever Knights along with Ben. Vilgax gets Diagon's heart and ends up being sucked into Diagon's own parallel dimension.

Azmuth reveals in his memories how Old George had acquired the great sword, Ascalon, and how he sealed Diagon the first time millennia ago. In addition, he reveals the real reasons for creating the great and powerful Omnitrix and Ultimatrix.

Techadon Weapon Master 13 arrives on Earth and demands to have the Ultimatrix. A malfunction grants Gwen and Kevin the forms and unique abilities of some of Ben's aliens.

With the help of Hex, Gwen and the gang set out to rescue Charmcaster from her home world of Ledgerdomain. However, they are shocked to learn that Charmcaster's intentions bode ill for them all.

Darkstar romantically charms Charmcaster and uses her intensely strong magical strength and abilities to his own evil advantage to absorb all of the infinite amounts of mystical energies from Ledgerdomain itself. Meanwhile, Gwen and Kevin have a disagreement over the protection of one of her spellbooks.

Jennifer Nocturne runs away with Captain Nemesis after freeing him from jail in hopes of creating a new life with him. Ben and Gwen pursue them, thinking Jennifer has been held against her will.

Dr. Animo returns with a plot to transform eggs into pterodactyls.

Albedo returns and infects Ben with a Cassiopeian Dream Eater, trapping him into a dream world where he kept being attacked by several of his enemies.

The Forever Knights battle Diagon's Esoterica minions and Ben's plan to help the knights fails as they are, too, intent on fighting him to listen to reason.

Ben, Gwen, Kevin, and George try to stop Diagon's resurrection, but first, they must defeat the demon's herald: Vilgax, now merged with a Lucubra and is much stronger than ever. To make matters worse, Dagon releases a wave that transforms everyone on the planet into an Esoterica, save Ben, Gwen, Kevin, George, Julie, and Ship.

Ben fails to defeat the extradimensional Diagon, who proceeds to destroy Sir George by electrocuting him with dark lightning. Vilgax returns, capturing Diagon by Psyphon's power-absorbing machine. Psyphon proceeds to transfer Diagon's power to Vilgax, making the galactic conqueror into a nearly-unstoppable force. Ben wields George's sword, Ascalon, and uses it to drain Diagon's power from Vilgax. Reverted to his original form, Vilgax tries to corrupt Ben, asking what he plans to do with the combined power of Ascalon, Diagon, and the Ultimatrix but Gwen and Kevin both encourage Ben to resist Vilgax's temptation. Ben uses his infinite godly abilities to transform the Esoterica back into humans. Azmuth appears before them and asks Ben to return Ascalon and the Ultimatrix to him. He gives Ben a new version of the Omnitrix.

11-year-old Ben Tennyson faces off with a new enemy, a red Galvanic Mechamorph, Malware. Five years later, Kevin and Gwen leave when Gwen takes early enrollment in an Ivy League college, and Kevin moves to be near her. Ben is forced to fight crime alone, but Grandpa Max (Magister Tennyson - the commander of the Earth-base's Plumbers) gives him a new partner, rookie Plumber Rook Blonko. Ben and Rook end up in their first team-up when Mr. Baumann's store is targeted for destruction by three alien criminals (Bubble Helmet, Fistina, and Liam) as part of their protection racket. An intergalactic hunter named Khyber watches Ben from the shadows.

After stopping Bubble Helmet, Fistina, and Liam from blowing up Mr. Baumann's superstore, Ben and Rook discover an underground alien city named Undertown where they discover that Psyphon is behind the protection racket. At the same time, Khyber sends his pet in the form of Buglizard to hunt Ben.

The Megawhatts that Ben fought in his youth come back. This time, they need Ben's help when they are being used as a power source for the villain Fistrick and his gang.

Infiltrating the Plumbers' base, Khyber downloads footage of young Ben's encounter with a corrupted Mechamorph named Malware. This shows Malware's origins and Ben's first encounter with him when he attacks Galvan Prime.

Ben meets an alien con artist named Professor Blarney T. Hokestar whose miracle elixir is extracted from a small alien called a Screegit that is kept in his lab. When a Florauna activist named Pax convinces Ben to help him free the small alien from Hokestar's lab, chaos ensues when the nitrogen in Earth's atmosphere turns the exposed Screegit into a giant, acid-spitting monster with Ben having to keep it from wrecking the city.

Dr. Animo has escaped his Plumber prison, and Ben and Rook must track him down before he transforms the world into his personal mutant ant farm.

Argit and the Vreedle Brothers are fighting for possession of a doomsday device. Ben uses the almighty Alien X's godly abilities to fully recreate the universe.

Ben and Rook come across elastic, hot-blooded aliens that plan to activate a volcano with a nuclear bomb engine. Ben later falls for a female alien named Esther.

In flashbacks, it is revealed that during a fight with 11-year-old Ben, Malware touched the Omnitrix symbol on Four Arms. After the battle, he went to Dr. Psychobos and made him create a prototype Omnitrix, the Nemetrix. Dr. Psychobos plans to create the Nemetrix so that he can best his rival Azmuth and prove that the Cerebrocrustaceans are far much smarter than the Galvans. In the present, after a heated argument, Ben and Rook go their separate ways giving Khyber his best chance to capture Ben. After a long battle, Ben is forcibly changed back into his human form and supposedly falls unconscious.

Khyber tells Ben that he needs different alien DNA to complete the evil incomplete version of the Omnitrix, the Nemetrix. He also reveals that Dr. Psychobos assigned him to hunt down various species for DNA to transfer it to the Nemetrix and also tells Ben that the reason Dr. Psychobos is creating an evil Omnitrix is because of the orders from Malware. After Ben breaks free, a brawl breaks out leaving Khyber the victor. Rook breaks in and saves Ben and the duo then reveals to Khyber that they orchestrated the whole "fight" at Undertown and Ben only let Khyber capture him so he can lead them to his ship. Ben and Rook accidentally crash Khyber's ship eliminating the DNA to complete the Nemetrix. Khyber and his dog emerge unharmed as Malware and Dr. Psychobos arrive.

While Khyber struggles to control his dog's transformations, Dr. Psychobos tells Malware that he will need a part of the Omnitrix to fix it. This causes Dr. Psychobos to infiltrate the Plumber's base on Earth and steal a part from Ben's Omnitrix causing it to malfunction. The malfunctioning of the Omnitrix causes its powers to leak into Psyphon, Bubble Helmet, Fistina, and Liam giving them abilities very similar to the Omnitrix aliens.

Gwen and Kevin pay Ben a surprise visit; a Tetramand princess and her father's fleet of warships threaten the Earth.

Magister Patelliday is captured by pirates.

Ben and Rook must stop Trumbipulor from gaining absolute power. Yet the main plot occurs when Blukic and Driba set out to find a Mr. Smoothy's after seeing an advertisement for their new grasshopper smoothies and have many misadventures along the way with one of them tying into fighting Trumbipulor's robotic rats.

Ben and Rook are attacked by Khyber and his dog (which can now transform at will without Khyber's whistling) at the Old Bellwood Days Festival. In a flashback, it is also revealed how Malware had obtained his current mutated Galvanic Mechamorph form.

An old rival of Ben Tennyson named Billy Billions turns Ben and Rook into kids again while bringing Dimension 12 robots to Earth and controlling them.

Ben and Rook visit Rook's family on Revonnah during the Amber Ogia harvest. Meanwhile, Fistrick trains the planet's local rodents called the Muroids to steal the Amber Ogia as fuel for the planet-destroying satellite in his possession.

Eon returns and switches Ben's mind with his younger self as part of a plot to take over the timelines. It's up to Paradox, and the two Gwens from the past and present, to help the Bens' regain their rightful minds and help to defeat Eon.

Ben takes Blukic and Driba to look for the 23rd Mr. Smoothy restaurant. After, Ben, Blukic, and Driba enter the 23rd Mr. Smoothy restaurant that keeps disappearing, they find it run by Professor Blarney T. Hokestar who is using a dimensional device to move the restaurant to different dimensions. In one dimension, Ben meets an alternate version of himself who is very rich, names his aliens differently and has lost his beloved Grandpa Max.

After Ben accidentally destroyed Mr. Baumann's car during his fight with Psyphon's minion, Thunderpig, Mr. Baumann orders Ben to make deliveries for him without using the Omnitrix. When Ben unknowingly gets the Dwarf Star (a massive power source that was going to be sold at Psyphon's auction) in his possession, Ben must fight off Pysphon, Fistina, Zombozo, Trumbipular, the Vreedle Brothers, Fistrick, Vulkanus, Sunder, and Seebik to keep them from getting absolute power.

The Faction infiltrates a Galvan museum and try to take Azmuth but instead he teleports Ben and Rook to the museum. Khyber and Dr. Psychobos have a fight and Zed turns to Vicetopus and takes Dr. Psychobos. Ben reveals when he was 11, he had a fight with Malware and he took Feedback out from the Omnitrix and killed him. Angered, Ben puts his Omnitrix into Malware and he seemingly perished from the overload. Khyber takes the Nemetrix from Zed and mysteriously escapes. The group arrests Dr. Psychobos, who warns Azmuth that the planet and his species are about to become extinct. Galvan Prime's moon, Galvan B, explodes with everyone shocked and surprised.

Galvan Prime's mechamorph ecosystem is engulfed by Malware and Galvan Prime is destroyed. A gigantic Malware then accumulates on the surface of Galvan. Ben is absorbed into Malware and confronts his 11-year-old counterpart. They both forgive each other for the incident with Malware and 16-year-old Ben regains Feedback. There is a shower of mechamorphs leading to Malware becoming its original size. Malware is finally defeated and destroyed by Feedback with the intense electrical power from the repaired double helix.

The Gourmand Queen is captured by Incurseans, forcing Ben and Rook to rally her feuding subjects to save her.

Ben and Rook escort Vilgax to a maximum-security prison planet, but the Incurseans have other plans.

Princess Attea springs Dr. Psychobos from prison to help her lead an invasion of Revonnah.

Incurseans take control of Earth, so Rook and the Plumbers must stop them, while Ben is somehow missing.

Ben, Rook, Gwen, and Kevin must find a solution to stop the Incurseans once and for all.

Princess Looma attacks Ester's village, forcing Ben, Rook, Fistina and Julie to stop her. In the meantime, Ben is shocked as Julie has gotten a new boyfriend.

With Plumber agents trapped in Incursean territory, Ben and Rook must employ the services of Rad Dudesman, the roughest, toughest smuggler in the galaxy.

Dr. Animo remembers the time he had taken control of the Plumbers Headquarters inside Mount Rushmore with bugs that easily hack computer codes, planning to mutate everyone on Earth into grotesque, monstrous creatures resembling him.

The Secret Saturdays come to Bellwood to investigate a rash of chupacabra attacks. Ben and Rook assist, finding the chupacabras have been draining aliens of their lifeforce. They soon discover that the chupacabras are being controlled by Dr. Animo, who is an old business associate of V.V. Argost. Using the alien lifeforce, Animo successfully revives Argost in a mis-matched hybrid body. Now Ben, Rook, and the Saturdays must work together to turn the tables on the alliance of Dr. Animo and V.V. Argost when they plan to make an army of "Franken-Cryptids."

Ben as Gravattack attempts to moderate a fragile peace treaty, but must endure the attacks of tiny alien fleas, which have inhabited his body. Rook shrinks down in attempt to get the fleas off him before the peace treaty is ruined. But it turns out that the Lewodon named Poltroon, sent the fleas onto Gravattack to destroy his core, causing a meltdown in attempt to destroy both the Lewodons and the Appoplexians, therefore causing a war between the two species and taking power to destroy his enemies. Now Rook must find a way to change Ben back before they are destroyed and to stop Poltroon.

Octagon and Rhomboid Vreedle decide to prove themselves to Ma Vreedle by pulling off successful crimes; to ensure success in numbers, they take a Pretty Boy Vreedle to assist them under the belief that Ma won't notice one out of the several others missing. When Ma does discover this, she threatens to blow up the sun if the Plumbers don't find Pretty Boy. Meanwhile Ben tries to hide from his mom so he won't get seconds on the dinner that he hates.

The Forever Knights are back, led by the new Forever King, Dr. Joseph Chadwick, and plan to erase all alien DNA on Earth. Jimmy Jones discovers that Will Harangue is helping the Forever Knights. After the Forever Knights are taken care of, Ben might have a fitting punishment in mind for Harangue.

While Rook and Kevin are at an auto show, Ben, Gwen, and cousin Lucy try to find out how Psyphon's thugs are getting Level 7 Plumber technology. Gwen suspects that Lucy is the mole because of her shapeshifting abilities as a Sludgepuppy, and her love of tricks when she was younger, but it turns out that it is an old enemy: Gorvan.

While attending an intergalactic auto show on Khoros, Kevin, Rook and Argit run into OTTO, an old enemy of Kevin and Argit that stranded them alone in the Null Void. But OTTO and Violent Offenders end up stealing some of the most expensive cars, and OTTO turns into a giant robot, leaving Ben having to stop him.

Albedo (who is disguised as Ben) seeks a device that will finally change him back into his Galvan form. Meanwhile, Ben (who has been disguised as Albedo by Khyber) is locked in Plumber HQ prison. It reveals Khyber has disguised Ben and Albedo as each other for their plan to work. Meanwhile Argit claims to be the hero of Undertown after stopping the Way Bads in "The Frogs of War".

After Ben falls for Albedo's trap, Grandpa Max and Rook search all over the galaxy looking for Ben. Meanwhile he's been secretly trapped on Khyber's hidden personal hunting preserve fighting Khyber's new pet that now wears the Nemetrix. But as Ben finds a way out, he has to deal with Albedo. When Grandpa Max and Rook arrive, they find that Albedo and Khyber have Azmuth as their captive.

Albedo took out Azmuth's brain through his cerebral vortex. With assistance from Gwen and Kevin, Ben, Rook, Max and Azmuth (whose supreme intelligence has been diminished) and the Plumbers must find a way off Khyber's Place, to get back to Earth and stop Albedo and Khyber from taking over the galaxy by absorbing Azmuth's brain sphere.

Ben, Rook, and Max have their hands full when Phil returns as a half-human half-Terroranchula creature as a side-effect of using the Nemetrix five years ago, and starts absorbing all of the electricity and lightning in Bellwood. But when he heads into Undertown's mini power-plant and starts to absorb the Megawatts, they must find a way to stop him.

Ben and Rook investigate a circus, which Ben decides to stay out of while Rook enjoys the show; however, he comes out looking like a clown. Ben gets him to Plumber HQ, suspecting that Zombozo is up to his old tricks; however, Zombozo has escaped his cell and the number of zombie clowns is growing. Now Ben must try to overcome his fear of clowns so that he can save the people of Bellwood.

After Gwen as Lucky Girl beats Punchinello, Ben and Rook visit her and Kevin at college, but Darkstar (disguised as student Dante) gets revenge by using Charmcaster's rock monsters, and creates a cult in order to use Gwen to open up a portal to Ledgerdomain to absorb all the mana to become even powerful.

Bill Gacks, an human plumber who resembles Vilgax (due to his beard), accidentally activates a weapon Vilgax set to attack Bellwood while fixing Pakmar's plumbing in Undertown. When Psyphon returns, he believes Bill is Vilgax, and, elated that his master has returned, pledges to help him in any way to destroy Bellwood. Meanwhile Ben and Rook try to stop Vilgax's squid monsters that the weapon accidentally released.

Ben's childhood crush, Kai Green, asks Ben and Rook for help when her grandfather is kidnapped by the Forever Knights who are after a mysterious sword all the way in London hidden in a secret room under the river.

Dr. Animo from the future return to the present to break his past-self out of prison, and to steal something from the SACT so that they can populate and rule the Earth with mutant animals. In order for Ben and Rook to stop him, they get assistance off someone from the future currently known as Chrono-Spanner.

Ben, Rook, Rad, and Hobble fly through the Anur System to deliver something before they end up crashing into Anur Transyl, needing a device to power-up their engine. But as they walk through the planet, due to Anur Transyl being all but closed to the rest of the universe, the Halloweenish residents see Ben and his group as the monsters. Ben learns that Zs'Skayr (Ghostfreak's real name) has orchestrated the delivery to bring himself and the mentally restored Dr. Viktor back to their home system with revenge as an added bonus.

Still stranded on Anur Transyl, Ben suffers from a serious zit problem that grows worse with each time he uses the Omnitrix. At the same time, Charmcaster proposes an alliance to defeat Zs'Skayr, since he stole the Alpha Rune from her. Also, a female Trasylian alien named Viktoria develops a crush on Ben, due to his terrible acne.

Zs'Skayr and his allies awaken the great evil Lord Transyl, where he asks to make an alliance to rule the universe, but just as they team up, they manage to hypnotize everyone on Anur Transyl, and Ben's team. Now with Ben's newest alien Whampire, Ben and Hobble must discover a way to defeat Lord Transyl, save everyone, and must fix their ship in order to get back to Earth.

As Ben and Rook go on a double date with Ester and Rayona (Rook's girlfriend back home), they encounter Nyancy Chan, who places Ben (as Rath) under her trance and uses him in a crime spree. Meanwhile, Princesses Looma and Attea are at odds about who will get to legally marry Ben's alien forms: Four Arms and Bullfrag.

Ben meets the ones responsible for his intergalactic TV show and the crew who makes this Ben 10 actor more famous than Ben himself. With Ben frustrated with this show on the air and taking his fame, Simian ends up hiring an alien collector known as Collectimus who turns things into training cards for his collection.

Eon and Vilgax team up and bring together a team of evil-parallel Bens, (consisting of Albedo, the black haired "Bad Ben", the Australian-accented, Mad Max reminiscent warlord Mad-Ben, the deformed, zombie-like Benzarro and the apathetic, gothic Nega-Ben) who go after a Ben who never got an Omnitrix (No Watch Ben). Professor Paradox helps Ben Prime (the main Ben) to find a team of good Bens (consisting of Ben 23, 10-year-old "Gwen 10" (from a timeline where she got the Omnitrix) and Ben Prime's future self, Ben 10,000) to fight back and save No Watch Ben. Things take a turn for the worse when Vilgax uses a Chronosapien time bomb to wipe out Ben in every other dimension apart from No Watch Ben. Before disappearing, Ben Prime gives his Omnitrix to No Watch Ben.

No Watch Ben and Professor Paradox return to the point where the Ben 10 multiverse began: when Ben Prime first acquired the prototype Omnitrix six years ago. From there the two start to unite the good Bens to fight Vilgax and the evil Bens. After the team is put together, Paradox sends the other Tennysons who had their watches to fight and keeps No Watch Ben in the event horizon. After Vilgax destroys the multiverse, No Watch Ben returns to fight him moments after his rescue and turns into Clockwork to undo the multiverse wipeout. Clockwork sends the Evil Bens back to their respective timelines, then returns the Omnitrix to Ben Prime, and the Good Bens and Gwen take turns beating Vilgax.

Billy Billions seeks the help of Mazuma, Will Harangue, Kangaroo Kommando, and Captain Nemesis to form the team The Vengers to take down Ben, make him look bad in front of all of Bellwood, and claim the title as the protectors of Bellwood.

With Spanner's unexpected return, Ben and Rook think Jimmy Jones is Spanner because they never appear at the same time. Meanwhile Argit holds a weapon that can create Techadons at an unlimited rate with the use of water, and Psyphon and his Bounty Hunters are after the weapon, but when Argit swallows it, they have to tell Argit to "cough it up" or he won't stop puking up armies of Techadons nonstop.

The Rooters, the Black Ops wing of the Plumbers from the Null Void, hybrid aliens with unique abilities, head to the Plumbers' Base, looking for Kevin for his property-absorbing powers. Ben sneaks out to get Kevin, who claims to not know the Rooters, but after a run in with them Kevin bumps heads with their leader, Proctor Servantis, he begins to recollect hidden memories.

An old friend of Blukic and Driba's asks to get back a super powerful weapon needed to stop an old villain of Blukic and Driba and Max's, who's attacking Area 51. But with the weapon hidden back in Area 51, Ben and the team must go retrieve it before this strange old/new threat can retrieve the weapon.

Rook is under the influence of Fistrick's "bro" essence, and starts to act like a bro. He and Ben infiltrate an alien fight club to claim the Golden Fist.

Ben gets dragged into intergalactic court by the other Celestialsapiens for recreating the whole universe and all of existence previously in "So Long and Thanks for All the Smoothies!". In the end, the court rules in Ben's favor that Alien X was not controlled by Ben but by Belicius and Serena.

Kevin and Argit attempt to warn the amalgam kids about the Rooters' intentions before they can hunt them. Kevin gathers Alan, and Gwen, Ben, and Rook gather Helen and Manny. The Amalgam kids learn they aren't plumber hybrids, and Kevin goes out into the Null Void alone to put an end to the Rooters, but when Ben and the gang bring the Amalgam Kids, it turns them against Ben, and later Proctor (head of the Rooters) ends up persuading Kevin into joining his side to take down Ben.

After the Rooters have turned Kevin and the amalgam kids against Ben, they attend to hunt after him while Ben, Gwen, Rook, Argit, and Zed try to escape the Null Void.

Ben's country cousin Clyde Fife wants to become a hero like Ben.

Master Kundo, Rook's former teacher is willing to save Revonnahgander traditions at any cost by preventing Rook's sister, Rook Sharr from going to the Plumber Academy so she wouldn't be able to become a Plumber.

Charmcaster attacks Gwen at Friedkin University, wanting to obtain Hex's mystical Staff of Ages through any means necessary, while Kevin and Rook try to make Kevin's car completely indestructible so that nothing can destroy it.

After Mr. Baumann, the grouchy storekeeper, realizes from Ben that his temper comes from being lonely he starts soul-searching. Eventually he stumbles across a secret not from this earth.

When Ester invites Ben (who brings along Rook to her dismay) to a museum exhibit displaying alien artifacts, they encounter Ben's former crush Kai. When Ester discovers their relationship she immediately becomes jealous of her. The four of them are forced to team up, however, when a priceless exhibit that Kai put on display is stolen. Chrono Spanner also reappears again, this time trying to convince Ben that he's "destined" to marry Kai, to Ester's chagrin. Spanner's identity can be deduced from this episode.

Fistrick orchestrates a series of robberies while wearing ID masks programmed to make him and his compatriots to resemble Ben. When the real Ben discovers what's going on he decides to go undercover with Rook's help and investigate Fistrick's workout gym to find out what's going on. As this is all happening, Ben is struggling with his obsessive cravings for chili fries and meatball subs.

With the help of the con-artist Simian, Argit starts a secure transport firm called "Argistix Securities" employing a group of Techadons as workers. Ben immediately becomes suspicious of Argit's business, considering the latter's history.

Pa Vreedle reunites with Ma for all-out, total cosmic destruction! Meanwhile, Rhomboid and Octagon try to impress Ma and Pa Vreedle like Isosceles and Parallelogram Vreedle always does.

A dangerous Chronosapien named Maltruant attempts to obtain total control over the space-time continuum with the help of an old relic called the Key to Time; Ben 23 is sent by the Azmuth of his dimension to Ben Prime's dimension in order for the latter to act as a "mentor" to the former.

With the help of Dr. Psychobos, Ben 23 and Ben Prime successfully stage a breakout and a revolution in Mad Ben's labor camp.

In a flashback to Ben and Gwen's younger days when they were eleven, Zs'Skayr returns with a plan to have his fellow Ectonurites to possess the inhabitants of Bellwood to develop a device to permanently block out the sunlight on Earth so he can colonize the planet with more Ectonurites.

Khyber teams up with a Slimebiote, a DNA-eating parasite, named Skurd so he can safely use the Nemetrix to eliminate Ben. The plan backfires when Skurd discovers the vast amount of DNA he can consume from the Omnitrix and decides to latch onto it, to both Khyber and Ben's dismay. As Khyber goes mad from extended use of the Nemetrix, Skurd's merge with Ben allows for recombination of aliens mid-fight to give a combative edge, giving Rook time to remove the Nemetrix with very minimal damage to Khyber.

Exo-Skull, Subdora and Eon attack a hidden underground cavern to retrieve a rare egg of a Time Beast. Professor Paradox and Ben 10,000 teams up with Ben and Rook to stop the Time Beast. Rook, Ben and Skurd go after the Time Beast while Ben 10,000 and Professor Paradox fight Exo-Skull and Subdora. However, a series of mistakes lead the five of them to constantly travel through time to correct their actions. Eventually the time beast is captured, but at the end of the episode, Eon delivers two Time Beast eggs to Maltruant.

During Kai's search for the Temple of the Sky, she reluctantly teams up with Ben, Skurd, and Rook at the insistence of Kai's grandfather. As they search, Ben teases Kai about Spanner telling them they are married in the future, and as he shows her more clues they show more attraction, despite Kai denying Spanner's prediction. Upon reaching the temple and finding the relic inside, the guardian of the temple is an eons old Galvan tasked with protecting a dangerous component of Maltruant by Professor Paradox. Maltruant still succeeds in gaining the second of his three lost components.

Charmcaster traps Gwen in Ledgerdomain to exact her revenge once and for all, turning her into a stone totem. When she attempts to take over Gwen's headquarters at Friedkin University, Ben, Kevin and Rook fight back with the aid of the great sorcerer Bezel. Charmcaster is eventually defeated and turned into a totem herself, trapped in her own bag, which restores Gwen, Hex, Adwaita, and Darkstar to normal. Darkstar is arrested, Adwaita escapes, and Charmcaster is kept in Hex and Gwen's custody under the hope that she will see the error of her ways someday.

While Rook is stuck on graveyard shift at Plumber HQ, his sensei Kundo returns as a cyborg to purge the galaxy of technological influence. Ben and Max take a massive Plumber squadron to stop Yeta, a female Shocksquach alien, from continuing her criminal destruction. They later find HQ on lockdown because of Kundo and try to break into the base to give Rook back up. Fistina, the only prisoner, is deputized by Rook so as to help defeat Kundo. Following Kundo's defeat, Rook is effectively promoted to Magister and Fistina is allowed to go to the academy following her time served.

Ben finally manages to rid himself of Skurd, just when he needs the Slimebiote most. Vilgax and Albedo team up to steal Malware's calcified husk to convert into a war armor for Vilgax to defeat Ben. As Ben fights Vilgax, he realizes how much he needs Skurd to help him, while Azmuth, Luhley, Blukic and Driba fight Albedo. Azmuth uses a device he made years ago which disables Albedo's Ultimatrix and frees Skurd, in time to merge with Ben and defeat Vilgax. Ben thanks Skurd for his rescue, while Luhley decides to go on a date with Driba, while having her cousin date Blukic. In space, Vilgax's stone form oozes out what appears to be a reconstituted Malware.

Ben is being forced to be in an alien reality show called The Most Delicious Show and he watches as all the girls he'd met in his life to win the reality show's games to be the new Mrs. Tennyson. Soon, Kai Green wins the reality show, with Ester later revealing that she found another boyfriend–Sunny's old sweetheart Antonio.

In the future, Ben 10,000 and Kai Tennyson are at Plumbers' Headquarters having a party for Grandpa Max because he is retiring from the Plumbers and Rook is being promoted to be in charge of the Plumbers until Maltruant, Exo-Skull and Subdora secretly attacks Plumbers' Headquarters to get the Annihilaarg and the Dwarf Star for Maltruant to become stronger. Ben 10,000 and Kai both discover that their ally Chrono Spanner is actually their own son, Ken Tennyson.

Following Maltruant through the time stream, Ben has an adventure with George Washington, in 1773, fighting Maltruant and Vilgax. After defeating Vilgax, Ben and Rook chase Maltruant in the time stream to the beginning of time itself onto the starship of the Contemelia (the creators of the Annihilaarg) where Maltruant attempts to create a universe of his own using his own Anihilaarg. In a climactic battle, using the power of Feedback, Ben absorbs the Dwarf Star-powered Anihilaarg and uses its immensely strong, destructive power to defeat Maltruant, trapping him in a time loop that will result in him reliving the events of the Time War over and over for eternity. Back on Earth, Ben decides to go on a road trip across the recreated universe with Rook, Gwen and Kevin, concluding the series.