Five years have passed, and 15-year-old Ben Tennyson decides to wear the OMNITRIX once more, only to find that it has altered his DNA, allowing him to morph into 10 entirely new aliens. Accompanied by his super-powered cousin Gwen Tennyson and his once-foe, now ally, Kevin Levin, Ben embarks on a quest to locate his missing Grandpa Max. To rescue his grandfather, Ben must overcome the malevolent DNALIENS, a formidable alien species determined to annihilate the galaxy, beginning with Earth.