It's been five years since Ben last used the Omnitrix, but when Grandpa Max disappears, Ben must be a hero again.

Ben, Gwen, and Kevin encounter a strange ship in the middle of the desert and discover the Highbreed and the DNAliens.

Gwen picks up a distress call from Grandpa Max's Plumber Badge and traces its location to an alien weather station that's freezing the planet.

Kevin meets up with an old `friend' to get some secret, top-level alien technology, but in doing so, Ben and Gwen think that he has gone back to his bad, old ways.

Ben, Gwen and Kevin want to recruit new members to join the team. Michael Morningstar, who is first on the list of allies, seems to be a good candidate, but Kevin is suspicious of him.

Gwen's brother is in trouble and she asks Ben and Kevin to help her find him. While searching for him, they come across parasites that turn people into DNAliens.