Accompanied by her husband, son and daughter, Adelaide Wilson returns to the beachfront home where she grew up as a child. Haunted by a traumatic experience from the past, Adelaide grows increasingly concerned that something bad is going to happen. Her worst fears soon become a reality when four masked strangers descend upon the house, forcing the Wilsons into a fight for survival. When the masks come off, the family is horrified to learn that each attacker takes the appearance of one of them.