Out in space on a desolate planet, the shape-shifting bounty hunters Ug and Lee and their human companion Charlie McFadden search for a vicious, worm-like creature. After killing the beast, they depart the planet. Soon afterwards, they receive a new assignment by Zanti, head of the High Council. He tells them that Critters are still on Earth and must be destroyed. With that, they set a course for Earth. Noticing Charlie brooding, Ug inquires what is wrong. Charlie states his reluctance to going back after two years and asks, concerned, whether they would leave him there. Ug assures him they have no such intentions.