Sisters is a good psychological murder melo- drama, starring Margot Kidder as the schizoid half of Siamese twins, and Jennifer Salt as a news hen driven to terror in her investigation of a bloody murder. Brian De Palma’s direction emphasizes exploitation values which do not fully mask script weakness.
Kidder, paired with Lisle Wilson on a TV game show (neatly satirized in opening scene), later invites him over for the night. Next morning, in a nervous state and after a voiceover dialog in French with another person never seen, Kidder slashes Wilson with a butcher knife.
Salt views the murdered man’s agonies from a nearby window, and doggedly pursues the case despite incredulity of detective Dolph Sweet but with assistance of private eye Charles Durning.