A group of male friends become obsessed with five mysterious sisters who are sheltered by their strict, religious parents in suburban Detroit in the mid 1970s.

A group of male friends become obsessed with five mysterious sisters who are sheltered by their strict, religious parents in suburban Detroit in the mid 1970s.

Thirteen-year-old Becky Hopper, who recently experienced a traumatic event, is interviewed about a disturbing incident at her family's house. Despite having flashbacks, Becky feigns memory loss. Two weeks earlier, Becky, dealing with bullying and her mother's death, accompanies her father on a trip to her mother's old lakefront home. A dangerous prisoner, Dominick, and his gang invade the house, taking the family hostage. Becky escapes and confronts the intruders using a key. A violent showdown ensues.