Five years after the original Ben 10 series, a matured 15-year-old Ben Tennyson has removed the Omnitrix and lives a normal high school life. Visiting the Rust Bucket to see his Grandpa Max, Ben finds Max missing and encounters a mysterious alien which flees. Searching the RV, Ben finds a message left by Max claiming that he is investigating renewed alien activity on Earth, and that he has the Omnitrix. Ben confirms that the Omnitrix is still in his bedroom, and deduces that Max was hinting for Ben to put the Omnitrix back on. Ben consults his cousin Gwen, and the two are confronted by Magister Labrid, a Plumber who was aiding Max in his investigation before going missing. They agree to work together to find Max, and Ben puts the Omnitrix back on. The trio ambush an illegal trade between the Forever Knights and a group of the aliens who attacked Ben. During the battle, the Omnitrix recalibrates, giving Ben access to ten new alien forms. Ben is then attacked by his old nemesis Kevin Levin, the broker of the trade, whom he defeats. Kevin reluctantly agrees to help track down the Forever Knights who had fled, and the group travels to a Forever Knight castle, where they encounter a robotic dragon.