Young sailor Alex Winkler walks the streets of New York late one night, unaware of how $1,400 in cash ended up in his pocket. Alex, a radio specialist scheduled to leave at dawn for duty in Norfolk, Virginia, wanders into a dance hall and meets taxi dancer June Goffe. Feeling sympathy for the naïve Alex, June invites him for a sandwich at her place. There Alex confesses to June that, although he has no recollection of the evening's events, he must have stolen the $1,400 from Edna Bartelli after her brother fleeced him in a card game and she plied him with drinks. A guilt-ridden Alex persuades June to accompany him to Edna's apartment at 51st and Lexington, and there Alex discovers Edna's strangled body in the living room. Although the tough-talking June tries to reassure him of his innocence, Alex is torn with doubt and is convinced that the police will arrest him. Again, June chooses to help Alex and suggests that they think like the killer in order to deduce his whereabouts. At the corner soda fountain, June finds out that a blonde with a limp left the counter in a rush and, posing as the blonde's sister, orders the taxi cab that picked up the blonde to take her to the blonde's destination. While June questions Helen Robinson, the blonde, about her activities at 51st and Lexington, Alex pursues a distraught man in a taxi cab. Alex soon learns that the man raced off because his cat was choking and orders his cab back to Edna's. Although June concludes that Helen knows nothing about Edna, Helen discusses Edna's murder with her tense husband Jerry after June leaves. When June returns to Edna's apartment, she finds Alex there with his sympathetic cab driver, Gus Hoffman. Gus tries to convince Alex to forget about Edna, but June insists that Alex be cleared of all suspicion. After the trio discovers a stack of love letters that Edna used for blackmailing purposes, a gun-wielding woman, Mrs. Nan Raymond, sneaks into the apartment. Nan grabs Edna's letters, but drops them as she flees after being confronted by Gus. Alex then calls Lester Brady, a theatrical producer whose bounced check to Edna they also find, and makes an appointment with him. Nan, meanwhile, goes to see Brady, her lover, and tells him about Edna, who was blackmailing her over the affair. Hoping to retrieve the incriminating letters, Nan and Lester then inform Val Bartelli, Edna's gangster brother, about Edna's demise. When the unsuspecting Alex arrives at Lester's, Val accuses him of killing Edna, then reluctantly agrees to return with him to Edna's. There Val, unable to control his rage, starts to beat up Alex but is stopped by Gus, who returns with June after pursuing one of June's lovestruck dance partners. After Gus convinces Val that Alex is guiltless, he, Val, Alex, June, Nan and Lester go to a nightclub, where Edna's ex-husband, blind pianist Sleepy Parsons, is performing. Sleepy, who had been arguing with Edna just before her death, acts nervously, causing Val to explode with accusations. Val's subsequent attack on the sickly Sleepy, which leads to a fatal heart attack, attracts the police, and the entire group is brought in for questioning. At the same time, Edna's body is discovered by the police, and Alex comes under suspicion. After a calculating interrogation, the police force Alex to admit that he might have murdered Edna, but are startled when Jerry Thompson fully confesses to the crime. When the police unravel Jerry's confession, however, Gus finally admits that he killed Edna because she was having an affair with Jerry, his son-in-law, and wanted to save his daughter's marriage. The remorseful Jerry, in turn, confessed to protect Helen. His name cleared, Alex leaves on time for Norfolk with the faithful June at his side.