Sisters (1972)

Temperamental Alfred Hitchcock-y string instruments waiver and warble over the credits and images of fetuses, then it jumps abruptly into the low-budget, flatly-lit set which then zooms out with a slide whistle to show that it's intentionally flatly lit because it's a TV-show-within-a-movie. It's a TV gameshow about guessing whether some guy is going to spy on the naked blind girl in the locker room, which doesn't matter, but the girl and guy from TV go on a date.

She's Margot Kidder pretending to be french canadian with an extremely strong accent. She gets drunk, blabbers, and her ex-husband tries to drag her away but gets thrown out. She takes her date back to her place in Staten Island, shadowed quietly by the ex-husband. After considerable lead up, they start making out on her couch and we see the massive, disfiguring scar on her right side where, based on the film's title, we can presume a twin sister was once attached.

Her last two mystery pills get knocked down the drain while her new boyfriend is off taking his sweet time buying some birthday cake for Margot and her sister, and she writhes around on the bathroom floor while he's gone. He eventually returns and opens the cake box with a massive knife that the camera lingers on for a foreshadowingly long time. It is not but a few seconds more before somebody looking like Margot, but wearing different clothing, stabs him in the groin and mouth with that very same knife. He most assuredly does not survive. As he dies, the scene cuts to a most unusual vertical split screen, with one half from the perspective of a neighbor across the street, introducing the new Rear Window element.

In one split, the neighbor – a newspaper reporter – has called the cops because she witnessed an attempted murder. The cops come, but argue with her and delay going up to the apartment in question. In the other split, Margot Kidder and her ex-husband frantically clean up the mess, stuffing the corpse in a fold-out couch. Her ex-husband falls over Mr. Bean style, in a manner most unbefitting of the film. The two sides reunite too late, the cover-up complete. The cops are not amused. The camera very deliberately and unnaturally pans up and down to show us the blood spots that were missed, but nobody sees them. The neighbor finds the cake with two names on it, but drops it on the ground in her frenzied excitement.

The Rear Window imitation continues as the neighbor sends in a spy and watches from across the street through binoculars, anxiously peering from room to room and distracting them with phone calls. The spy makes a not-so-harrowing escape, embarks on a slow-speed couch chase, and delivers some documents about siamese twins. The neighbor heads off to watch films about surgical separation of a famous pair of twins. Entirely unsurprisingly, one of the twins reportedly died during the operation.

The ex-husband runs the local asylum, declares the reporter insane, and locks her up against her will. He wipes her mind with chemical hypnotism. You may remember this as the plot of American Horror Story: Asylum. This leads to a long series of false memories and flashbacks about the twins' separation, until Margot Kidder abruptly murders the ex-husband/doctor. The police question the reporter, but her hypnosis was successful and she doesn't remember a damned thing.

The obsessive private detective she hired is still tracking the corpse-filled couch across the continent when the film abruptly ends without conclusion. Each and every storyline ends with a wimper.