Anna, a young and energetic journalist, receives an obscene call from an unknown caller whom she mistakes for her boyfriend. As a result of this mistake she agrees to meet with the caller at a local bar. When her boyfriend doesn't show she inadvertently witnesses a murder in the women's bathroom. Soon she finds herself drawn into a mystery involving both the killer from the murder she witnessed, as well as the identity of the mysterious caller who continues to phone her and who she shares increasingly more personal conversations with during each subsequent call.