Sisters (1972)

Sisters (1972) is a psychological horror film by American director Brian De Palma. Advertising salesman Philip Woode earns a dinner for two at a Manhattan restaurant on a Candid Camera-style TV show. During the prank, he is charmed by Danielle Breton, a young French Canadian model and aspiring actress, who he agrees to take as his date. After their dinner, they head back to her Staten Island apartment for intimacy. The following morning, she reveals that her twin sister Dominique has arrived to celebrate their birthday. At her request, Philip runs to the drug store and picks up a birthday cake on his way back. However, upon returning to the apartment, he is tragically murdered by the deranged Dominique who had been pretending to be Danielle all along. As he writes ‘help’ in his own blood on the window before passing away, it becomes clear that he was fighting for his life until the very end.

The neighbor, reporter Grace Collier, contacts the police. Danielle’s ex-husband Emil helps her hide Philip’s body inside the sofabed. Grace and skeptical Detective Kelly, along with his partner, search Danielle’s apartment. However, Danielle maintains that she has been alone since the previous night. Convinced that Danielle is hiding something, Grace convinces her editor to let her investigate further, believing that the police are overlooking the case because Philip was black. She enlists the help of Larch, a private investigator, to gain entry into the apartment. Larch discovers the body inside the couch and also comes across a file from the Loisel Institute about Canada’s first conjoined twins, the Blanchion Twins. Upon further investigation, it is revealed that the twins were recently separated and Dominique apparently died during the operation.