At their lakeside vacation home, Ann, George and their son have unexpected visitors: two well-spoken, well-bred young men wearing polite smiles and preppy sportswear. The visitors want to play a game. "You bet that you'll be alive tomorrow at 9:00, and we bet that you'll be dead. OK?" As the terrorized family fights to survive, each plan is thwarted, each option closed, each hour closer to what could be the last.