The film tells the story of two roommates, Mike Carr and Johnny Dixon. Johnny, who suffered a head injury during the war, meets a girl named Estelle Mitchell, and begins to date her. When he finds out she's dating other men around town he dumps her and starts dating her sweet twin sister, Linda.
The story picks up when Mike Carr goes into Tim McGinnis’ bar in New York, to wait for Estelle, a woman he hasn’t met since her twin sister Linda was murdered six months earlier. He sits down and start having flashbacks of the events around Linda’s death:
Johnny Dixon, who once served together with Mike in the Army, and was his roommate at this point in time, had frequent nervous breakdowns. Johnny and Linda were a couple, and they were very much in love, but the twin sister, Estelle, wanted Johnny for herself. Estelle was quite determined to break the happy couple up, but in the meantime she was seeing Mike, who had a hard time resisting the vampy Estelle.
Mike only met Linda once, but in doing so, he realized that she was the sister he should have been putting his energy into catching, as she was the more innocently virtuous of the two twins.
But the twin sisters both wanted Johnny, and one night they got into a fight over him, after which Linda went to see Johnny on her own. Estelle tries to intercept and get to johnny’s first. Mike saw Estelle arrive at Johnny's before Linda had arrived. He stops Estelle from coming in between the two lovers, but when Mike returns home a couple of hours later, Estelle telephones Mike at her mother's request to say that Linda never came home and has been reported missing.
Mike sees Johnny, and he turns out to be drunk and distraught. He begs Mike to verify his alibi, and that he heard Linda whistle for a taxi and saw her leave. When the police arrive to the scene they find a buckle from Linda's trenchcoat on Johnny's apartment floor, and after finding Linda's body in the apartment building, they take Johnny in for questioning.
Mike passes by McGinniss's and finds another buckle outside the bathroom window. He goes to Johnny and mentions the possibility that Johnny’s memory might have failed him the night of the murder. While they are talking, the police arrive to arrest Johnny, and he panics. Mike helps out his friend, letting him escape out the back. In order to persuade Mike to give Johnny up, police detective Heller takes Mike to the morgue to show him Linda's trashed body. Heller then recounts the horrible details of Linda’s death: After being choked, Linda was pushed, still alive, into the chute of the trash incinerator, and when he was unable to fit her in the tight space, the murderer shoved her in and broke her neck. The murderer then pulled her out and put her in a barrel on the roof.
Mike is disgusted by this, but still doesn’t believe his friend murdered Linda. He convinces Johnny to come out of hiding and clear his name. As they arrive home, Estelle is waiting for them with a man called Alex Tremholt, who has been renting a room at the Mitchells' since the twins were young.
While they are there, Mike hears a woman whistle for a taxi, and realizes that must be the same woman they heard the night of the murder. When Tremholt sees Johnny, he insists on calling the police to arrest him, but Johnny escapes once more. Detective Heller arrives and suggests Tremholt of having a long-standing, unrequited love for Estelle and of killing the innocent Linda, whom he mistook for Estelle, the object of his desire. With the truth being revealed, Mike hurries off to tell Johnny he is in the clear and just manages to stop him from hanging himself.
Back in the present, Mike drags Estelle to his old apartment and insinuates that she committed the murder. When he enters the flat, however, Heller is waiting to arrest him. He reveals that Jake, the apartment janitor, recently found Linda's neck scarf in the incinerator chute with Mike's fingerprints all over it. It turns out that Mike killed Linda, believing she was Estelle. After telling Mike that Tremholt's arrest was only a trick, Heller accompanies Mike down the stairs and past Estelle into the night.Bonita Granville as Estelle Mitchell/Linda Mitchell
Don Castle as Mike Carr
Regis Toomey as Detective Heller
John Litel as Alex Tremholt
Wally Cassell as Johnny Dixon
Film critic Dennis Schwartz gave the film a somewhat positive review, writing, "John Reinhardt economically directs a crisp crime thriller from the screenplay by Robert R. Presnell, Sr. that is based on the short story "Two Men in a Furnished Room" by Cornell Woolrich. Though the surprise ending is hardly convincing or for that matter original (Robert Siodmak's The Dark Mirror covered the same territory of identical twins in a superior fashion), and the acting was rather stiff, nevertheless this cheapie Monogram flick always kept me interested in the twisty plot and was quite engaging as it adequately covered the film noir conventions of following the dark sides of the main characters."