A terrified young baby-sitter...an incessantly ringing phone...and whispered threats set the stage for one of the most suspenseful thrillers ever filmed. Carol Kane stars as the baby-sitter who is tormented by a series of ominous phone calls until a compulsive cop (Charles Durning) is brought on the scene to apprehend the psychotic killer. Seven years later, however, the nightmare begins again when the madman returns to mercilessly haunt Kane, now a wife and mother. No longer a naive girl, though still terrified, but prepared, she moves boldly to thwart the maniac’s attack in scenes that culminate in a nerve-shattering conclusion.