Detective Wilson has a rough morning at home, with his wife Sandi nagging him about toilet seats, recycling, and dishes. He is rerouted to a crime scene in Queens, where plumber Leonard Crocker has stabbed his wife Arlene to death. Crocker calmly confessed to officers and now sits handcuffed in an interview room.

During interrogation, Crocker insists the woman he killed wasn't really his wife but an alien that replaced her. He explains a dark-web theory: aliens cross space as pure mind, take over human bodies (killing the original occupant), and gradually become short-tempered and critical, eventually dominating their partners. A computer-detected trigger produces a brief 'red screen' that exposes them. Crocker claims he saw the red screen on Arlene. Wilson dismisses him as insane and ends the interview.

Wilson arrives home late to a dried-out dinner and Sandi's irritation about forgotten dry cleaning. Captain Alvarez calls: Crocker stabbed himself in the jugular with a pencil at intake, dying despite fighting to stay conscious. Sandi softens, scrambles him eggs and bacon, and they laugh together.

That night they make love for the first time in over a month. Sandi asks for a cigarette and confesses she's been hostile because she's entering early menopause at thirty-nine, feeling old and unlovable. Wilson comforts her, telling her he loves her. As Sandi reaches past him to turn off the light, his phone screen briefly flashes red. In the dark, Sandi smiles.