Sheen Estevez, best pal and frequent sidekick of Jimmy Neutron ("The Adventures of Jimmy Neutron: Boy Genius"), takes Jimmy's top-secret spaceship out for a spin and winds up crashing it onto the planet Zeenu. He wants to go home, but he's more than four million light years away, and the spaceship needs repairs. Where's Jimmy when you need him? While he tries to patch the spaceship back together himself, Sheen makes a lot of friends — and one enemy. In the crash, Sheen destroyed the home of an evil villain named Dorkus, who is vowing revenge on the pesky earthling. Still, things could be worse — the ruler of Zeenu, after all, thinks that Sheen must be a being of superior intellect sent from the heavens.