As Gwen applies to a prestigious Prep School, the circus freaks attack the school to get some quick cash. Ben foils a crime, and returns to find the circus has disappeared, Grandpa Max is acting strange, and Gwen has vanished. Ben goes on a road trip with his Grandfather, and cousin Gwen for summer vacation. Team Tennyson must stop Ghostfreak's plans. Now the Tennysons have two superheros in the family.
Soon she finds out it's a magic charm, and everything's going her way. Gwen has to escape and get her family to realize a switch has taken place. Ben gives her a souvenir. The Tennyson's start their summer vacation, and go to the camp ground. Ben approaches the remains, and a device attach's itself to his wrist. The Tennyson pick up Cooper, the grandson of a fellow plumber.
Some of Ben's old enemies attack a school bus. It's a rainy day, Ben challenges Gwen to a game of Sumo Samurai Slamdown. Ben foils Hex's attempt to steal a spell book, the museum gives him some souvenirs. Now he can change into 10 different alien creatures. It's a start of a perfect day for Ben. Ben wakes from a nightmare and says an alien is coming after him. Ben and Gwen end up inside the video game.
They find some alien interference, including the wolf, and mummy they had encountered earlier. Ben changes to Ghost Freak to fight them, but something has changed. While visiting Salem, the Tennysons encounter Charmcaster. Tetrax arrives, and tells them the omnitrix is broadcasting a self destruct signal. The Team must track down the werewolf to cure Ben. Tetrax arrives, drawn to the self-destruct signal broadcast by the Omnitrix.
Ben must learn to use the watch and each alien with forces intent on taking the watch. He takes Ben to go find the creator of the Omnitrix and fix it before it destroys itself, Ben, and the universe along with it. Now team Tennyson must keep Ben awake to prevent more chaos and find out who's behind Ben's sleep walking. Animation Science Fiction After a battle in a power plant, Ben notices something strange is happening with the omnitrix, but doesn't tell anyone. Ben tries to fight him, but the alien seems to know the Omnitrix's abilities. Gwen gets jealous of the attention Ben receives. Ben easily defeats them, the grateful cheerleader thank him.
Ben and Gwen are starting to turn into elves, Ben and Gwen must work together to free themselves and rescue Grandpa Max. The Omnitrix times out, and most of his Heroes no longer appear in the Omnitrix. After a fierce battle in a power plant with Dr. Tetrax arrives, drawn to the self-destruct signal broadcast by the Omnitrix. The alien from Ben's dream attacks them along the way. He takes Ben to go find the creator of the Omnitrix and fix it before it destroys itself, Ben, and the universe along with it with Gwen stowing aboard to help her cousin. When he changes back to Ben, he discovers Ghost Freak has escaped the Omnitrix, and wants to rule the world.
Ben must overcome his personal fear to rescue his cousin. Gwen is abducted through a portal. While Charmcaster as Gwen gathers ingredients for another transference spell, Gwen as Charmcaster gets sent to juvenile hall. The group goes to visit Aunt Vera whose now living in retirement community. That night they find Ben sleep walking, and causing havoc.
Ben participates in a hypnotists show. Ben witnesses some of the residents climbing walls, and other superhuman behavior. They hear the Circus Freaks are at Fort Knox and go to stop them. One person mistakes Grandpa for Santa Claus and uses him in his plans. This is an animated science fiction movie based on the American animated television series Ben 10.