An axe murderer terrorizes Chicago, striking six victims and leaving the city in a shiver of fear. The police, led by Police Inspector Gallagher and advised by psychiatrist Dr. Kurt Immelman, chase a wave of confounding clues, only to find each suspect shut down by a wall of paranoid, unreadable behavior. The investigation unfolds as a tense cat-and-mouse game, with a pattern that feels almost ritual in its precision, and the sense that the real mastermind is pulling strings from behind the scenes.
Across town, a shadowy command reaches a bird shop owner to kill dancer Edwina 'Eddie' Brown. She becomes the subject of the killer’s dangerous intrigue, moving under the glow of streetlamps as she walks home. Oliver Duffy, an actor who has just exited a play, notices the suspicious pursuit and steps in to warn her, only to be mistaken for a would-be suitor by the wary Edwina. A police officer detains Oliver, but it is soon clear that the danger extends far beyond a single stalking incident—the shop owner continues to shadow Edwina, driven by some unseen command.
Oliver refuses to walk away. He takes protective measures for Edwina, arranging a taxi to bring her home after each shift and staging a cunning decoy by placing a dummy in her bed while they keep watch in another room. When the shop owner finally forces entry and attacks the dummy with an axe, alarms sound and the man is captured. At the station, the attacker reveals a compulsive, obsessive habit: he rearranges slips of paper with meaningless writing, a clue that ties the night’s violence to a larger, chilling scheme. Oliver gives Edwina one of the puzzling slips as a keepsake, and the police place her in a hotel for safety.
The danger escalates as another intruder tries to break into Edwina’s room, this time with a fire axe. Oliver deduces that someone is manipulating vulnerable people to commit the murders, a hypnotic pattern that links all seven killings, with a curious detail: the seven murderers’ names all begin with the letter B.
To uncover the truth, Oliver decides to go undercover. He pretends to be schizophrenic to gain access to the psychiatric hospital where the arrested men are kept. Inside, he discovers a file cabinet and, scanning the entries under B, finds the seven men who carried out the axe murders. They are all patients of a psychiatrist at the hospital, [Dr. H. Santelle], and Oliver deduces that the true mastermind must be a psychiatrist manipulating his subjects. He escapes the ward, races to find Edwina, and brings her to a seminar attended by local psychiatrists with the goal of rooting out any connection to Santelle. Edwina does not recognize the crowd, but Santelle is nowhere to be found.
Afterward, they follow a lead to Santelle’s house. The butler is pressed into service to impersonate the doctor in surgical gown and mask, as they wait for the “L” train. Edwina remains uncertain, especially about a past liaison that she had in Paris, but a dangerous truth waits in the wings: the impostor is, in fact, Cesar, and he has been using Santelle’s name to claim a fortune in Chicago. The past love—Cesar—had left Edwina without warning, and now he reappears in dangerous disguise to kill for money.
As the clock ticks, Cesar confronts Edwina, locking her in a closet while he stalls for time. Oliver, battered and bruised, fights to reach her as police officers converge. The crucial clue appears when a piece of paper from the lunatic slips onto the floor, exposing Cesar’s ruse. In a fierce confrontation, Cesar fires at the officers, but [Police Inspector Gallagher] shoots him dead, ending the horrifying chain of murders.
With the danger vanquished, Oliver and Edwina are finally reunited and ready to marry, choosing to face the future together after a night of fear, deception, and a revelation about trust, memory, and the psychological shadows that can drive a killer.
