Cheryl Stratton, Ayn Ruymen, gets into an argument with her roommate Judy and decides to move out. Cheryl steals Judy's wallet and, instead of returning to her native Ohio, heads to downtown Los Angeles to the King Edward Hotel, a dilapidated landmark run by her maternal Aunt Martha, Lucille Benson, whom she has never met. The brisk, conservative Martha allows Cheryl to stay temporarily, insisting she not wander the hotel at night, and she brands the place as "one of the last respectable hotels in the city." > "one of the last respectable hotels in the city." The uneasy arrangement sets the tone for a tenancy steeped in secrecy and unease as Cheryl begins to notice how peculiar the hotel's guests and residents are.
Cheryl soon senses she is being watched. Judy's boyfriend, Len Travis Mike, arrives at the hotel seeking Cheryl and is met by Reverend Moon, Laurie Main, a guest who dresses as a priest and moves with a blunt, unconventional stride. Soon after, Mike is attacked in an upstairs hallway by an unseen assailant, and his head is decapitated before his body is discarded in the hotel furnace. Later, at dinner, Cheryl asks about Martha's daughter; Martha reveals the child was conceived via artificial insemination and implies that she is dead, a revelation that deepens Cheryl’s sense of isolation within the hotel’s walls.
Cheryl becomes drawn to George, a mysterious, handsome photographer who keeps a darkroom in the basement with Martha’s approval. George, played by John Ventantonio, begins leaving sexually charged notes for Cheryl, escalating to gifts of lingerie she is asked to model. Curious, Cheryl copies the hotel master keys and sneaks into George’s room, where she discovers a transparent inflatable sex doll and walls lined with avant-garde photos of nude women.
Judy Adams, Ann Gibbs, arrives at the hotel in search of Cheryl to reclaim her stolen money. Martha directs her to the basement darkroom, where an unseen assailant murders her. That night, Jeff, a young locksmith’s assistant who will later appear in the story, invites Cheryl on a date to a rock concert. Meanwhile, George fills his inflatable doll with water and attaches a blown-up headshot of Cheryl to its face, then injects the doll with his own blood via a hypodermic needle.
Tensions erupt during a quarrel between Martha and George, who accuses her of preventing him from pursuing the freedom he believes he deserves from “slatternly” female sexuality. That night, Cheryl dresses in the lingerie George left for her, and she is aware he watches her from a peephole as she undresses in the bathroom. After she leaves, George re-enters and takes back the lingerie, using it to dress his inflatable doll. The next morning, Martha discovers the discarded doll in the trash and orders Cheryl to return home. Jeff arrives later for his date with Cheryl, but the conversation reveals that he once dated a woman named Alice, a model who disappeared from the hotel and who was frightened by George. Cheryl, feeling protective of George, cancels the date and returns to the hotel.
Jeff follows Cheryl to the King Edward and confronts George, who is in his room listening to a taped recording of Alice’s murder. George bludgeons Jeff with a bottle and drags his body to the darkroom. When George returns to his room, he finds Cheryl posed on the bed in the lingerie, and he brandishes a hypodermic needle in a bid to stab her. An altercation ensues, and Cheryl unintentionally kills him by a falling stage light that smashes onto his head. Martha, alerted by the noise, enters the room and unbuttons George’s shirt to feel for a heartbeat—only to reveal that George has breasts and is a woman who has been cross-dressing and masquerading as a man. Martha proclaims that George’s spirit has been liberated from his body, and she had raised him as a man to shield him from female sexuality. She briefly offers Cheryl a chance to become her “new son,” but quickly turns on her, attacking with a large butcher knife.
The next day, Jeff’s father arrives with the police, who recover an unconscious Jeff in the darkroom beside Judy’s corpse. Upstairs, they discover George’s body alongside Martha’s corpse, Martha now dressed in Cheryl’s lingerie. As the police depart, Cheryl emerges from upstairs in a daze, repeating Martha’s creed about the King Edward being “one of the last respectable hotels in the city” and declaring that she must be extremely selective about its clientele.
