Melanie Layton plans an unforgettable Murder Mystery birthday party for her best friend Marshall at a remote deserted mansion on the San Francisco Peninsula. Using his love of Agatha Christie she arranges a party based on a Christie novel where the group is isolated for the weekend. Longtime friends gather to celebrate but it turns sour as old wounds and affairs are brought to light, capped off by the guest of honor’s murder. Originally planned as an entertaining private getaway the party is now a terrifying experience with each houseguest fearing for their life. Isolated due to party rules forbidding cell phones and cars, an attempt is made by a member of the group to go for help on foot. This attempt ends in failure when he is found badly wounded and unconscious. Tension and suspicion builds while Melanie searches for the murderer. Fearing that once the group has been rescued and they leave the estate, finding the killer will become impossible. As Melanie draws closer to the answer she becomes the next target and must rely on help to expose the perpetrator before her time runs out.