When teenagers Mike and Debbie see a comet crash outside their sleepy small town, they investigate and discover a pack of murderous aliens who look very much like circus clowns. They try to warn the local authorities, but everyone assumes their story is a prank. Meanwhile, the clowns set about harvesting and eating as many people as they can. It's not until they kidnap Debbie that Mike decides it's up to him to stop the clowns' bloody rampage.