Sam is the envy of her friends: enjoying the riches and comfort of her parents' estate, sheltered from the troubles of "the real world." What Sam doesn't have, however, is her parents' time. Her dad operates a high-flying financial business and his wife is a world-renowned painter. Left alone for yet another weekend, Sam invites her girlfriends - Heidi, Alex and Ella - round for a sleepover that escalates into a full blown party as Heidi invites her boyfriend, Toby, and his gang to join them. As drinks flow, it becomes clear that the strangers are after something else altogether inside Sam's house and will stop at nothing to get it. As the job gets botched, a psychotic sadist emerges amongst them and a bloodied cat-and-mouse chase ensues. The gang's leader, Josh, wreaks havoc but he isn't the only one who isn't what he says. Who will pay the highest price when karma comes back around to bite?