On her summer break from college, Shannon (Kristine Cofsky) throws a wild party at a secluded cottage. But while the guests party away, an escaped mental patient is waiting outside for his next victim to step out the door; after years in prison for committing a pair of grisly murders, he's ready to go at it again. When the partygoers who left the house fail to return, the remaining guests realize they're trapped -- if they leave, they could die.