As Christmas break begins, a group of sorority sisters make plans for the holiday. Jess (Olivia Hussey) and Barb (Margot Kidder) begin to receive anonymous, lascivious phone calls that put them on edge. Initially, Barb encourages the mysterious caller, but stops when he responds threateningly. Soon, Barb's friend Claire (Lynne Griffin) goes missing from the sorority house and a local adolescent girl is murdered, leading the girls to suspect a serial killer is on the loose. The police finally begin to get concerned when a teenage girl is found dead in the park - they set up a wiretap to the sorority house, but no one realises just how near the killer really is!