When Billy was a young boy, he was abused by his mother. His mother cheats on his father and she ends up killing his father. For years Billy is kept in the attic while she and her lover start a "new" family. Billy's mother becomes pregnant and has a daughter. She is treated with love, a love which Billy has never experienced. After years in the attic, Billy comes out and brutally murders his mother and her lover. Now living in Billy's childhood home, a group of eight sorority sisters and their house mother find themselves being harassed by threatening and intimidating mystery phone-calls during Christmas Break. Suddenly, one of the girls goes missing, while the rest of the girls begin being murdered one by one.