Sisters (released as Blood Sisters in the United Kingdom) is a 1972 American psychological horror film directed by Brian De Palma and starring Margot Kidder, Jennifer Salt, and Charles Durning. A French Canadian model's separated conjoined twin is suspected of having committed a brutal murder witnessed by a newspaper reporter in Staten Island, New York City. Co-written by De Palma and Louisa Rose, the screenplay for the film was inspired by the Soviet conjoined twins Masha and Dasha Krivoshlyapova and features narrative and visual references to several films by Alfred Hitchcock. Filmed on location in Staten Island, the film prominently features split-screen compositions (also present in subsequent De Palma films such as Carrie), and was scored by frequent Hitchcock collaborator Bernard Herrmann. Released in the spring of 1973, Sisters received praise from critics who noted its adept performances and use of homage. It marked the first thriller for De Palma, who followed it with other shocking, graphic thrillers, and went on to become a cult film in the years after its release. Plot Advertising salesman Philip Woode wins dinner for two at a Manhattan restaurant on a Candid Camera-style television show. Danielle Breton, a young French Canadian model and aspiring actress who was part of the prank, flirts with him and he agrees to take her as his date. After dinner, they retire to her apartment to have sex. The next morning, Danielle tells Philip that Dominique, her twin sister, has come to celebrate their birthday. At her request, he goes to the drug store to refill a prescription and picks up a birthday cake at a bakery on his way back. When he returns, he is stabbed to death by the crazed Dominique. Before he dies, he tries to alert a neighbor by writing "help" in his own blood on a window. The neighbor, a reporter named Grace Collier, calls the police. Danielle's ex-husband Emil helps her clean up and hide Philip's body by folding it inside the sofabed. Grace accompanies the skeptical Detective Kelly and his partner on a search of Danielle's apartment, but Danielle insists that she has been alone since last night. Certain that Danielle is hiding the murderer, Grace persuades her editor to let her investigate the story on the basis that the police are ignoring her because Philip was black. She hires Larch, a private investigator, to gain access to the apartment. He determines