Ben and Rook must stop Trumbipulor from gaining absolute power (which turned out to be peanuts since they can increase the size of Trumbipulor's kind). 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.

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.