Kill Theory (2009)

Plot

A group of college friends gathers at a remote vacation house to celebrate their graduation, but their festivities take a dark turn when a twisted killer invades their retreat. Faced with a horrifying ultimatum, they must engage in a brutal game where survival hinges on turning against each other. As trust erodes and paranoia escalates, the friends grapple with their morality while desperately trying to outwit the sadistic threat stalking them. Tension mounts, and alliances shift in this gripping tale of betrayal and survival.