ZIM dreams of greatness. Unfortunately, though, he's hopelessly inept as a space invader. Desperate to be rid of the annoying ZIM, his planet's leaders send him on a mission to infiltrate Earth, providing him with leftover, cobbled-together equipment. To their consternation, ZIM succeeds in setting up a base on Earth and infiltrating human culture, posing as a human child as he plots the planet's downfall. Only ZIM's archnemesis, Dib, recognizes that ZIM is an alien, and of course, nobody believes Dib's claims.