A mysterious meteor infected with a deadly alien plague brings chaos to a small hunting town in the feature-length directorial debut of screenwriter James Gunn (Scooby-Doo, Dawn of the Dead). Booted out of bed by his young, trophy-wife Starla (Elizabeth Banks), and in desperate need of some female companionship, wealthy Grant Grant (Michael Rooker) picks up bar local floozy Brenda (Brenda James) and heads into the woods for a hedonistic night of extramarital excitement. When a flaming meteor lights up the sky before crashing to the ground nearby, Grant's curiosity gets the best of him and he sets out to find the space rock. Subsequently infected with a rampaging space virus, which he passes along to Brenda, Grant transforms into a horrific, cow-munching monster and begins terrorizing the town. As thousands of squirmy space slugs burrow into the brains of the unsuspecting Wheelsy denizens creating an ever-amassing horde of mindless space zombies, panic grips the small town and it's up to Starla, Sheriff Bill Pardy (Nathan Fillion), and gung-ho mayor Jack MacReady (Gregg Henry) to put an end to the infection and save the planet.