Following their adventures in Utter Garbage, Dumpster, an idealistic young rat, and his sensible Uncle Binlid live happily in a clean city park, until the reappearance of Lord Vermin and his vile helpers. But Drumpster wants to look at the stars and soon the good rats are building a spaceship from rubbish. Propelled into space by the child-people in the audience, they meet Volga Ratskaya, a space laboratory rat. But they must battle with Lord Vermin before they can return safely.