A glamorous Broadway gambler named Alfred "Gloves" Donahue lounges at a restaurant, tinkering with toy military figures and imagining battles against Hitler. The mood shifts when the restaurant serves him a cheesecake that isn’t made by Mr. Miller, the baker who creates Gloves’ favorite dessert, leaving him visibly irritated. His mother, known as "Ma" Donahue, shares a nagging suspicion that something sinister has happened to Miller and that a bad omen looms over their neighborhood.
Gloves’ investigation begins at Miller’s bakery, where he discovers the baker’s body and realizes Miller is dead. The news travels quickly, and a young singer, Leda Hamilton, bolts from the shop at the first whisper of Miller’s death. Ma Donahue grows more convinced that the girl holds answers and tracks her down to a nightclub, where she creates a loud scene in protest over Miller’s death. Marty Callahan, the club’s co-owner, calls Gloves to handle the situation, setting the stage for a tense confrontation.
Inside the club, Gloves shares a drink with Leda, but their moment is interrupted when Pepi, the piano player, hustles Leda into a back room. Pepi shoots Joe Denning, Marty’s partner, before the duo vanish in a taxi. Gloves, stunned by the chaos, finds Joe dying and can only make out five fingers—an oblique clue about who took Leda. He leaves the scene with one of his gloves as a souvenir, a symbol of the growing mystery surrounding Miller’s death.
Suspected by both Marty and the police, Gloves follows the taxi’s route to an antiques auction house run by Hall Ebbing and his assistant Madame. Posing as a bidder, Gloves is spotted by Pepi, who knocks him unconscious and leaves him tied in a storage room with Sunshine, one of Gloves’ former allies who had been captured earlier. Leda later appears, frees Gloves and Sunshine, and they escape as crates are readied for shipment.
Their exit leads them into a nerve-wracking discovery: a room filled with maps, charts, a short-wave radio, and a portrait of Adolf Hitler. It becomes clear to Gloves and Leda that their captors are not mere criminals but “fivers”—Nazi fifth columnists. A notebook reveals Miller’s name, along with Leda Hamilton and the Jewish name Uda Hammel, and hints at the death of Leda’s father in Dachau. This revelation tightens their bond as they press on with Leda in tow.
The pair tearfully confide in each other as they flee through Central Park, pursued by Ebbing and his men. Leda explains that she has worked with Ebbing in order to save her father’s life, while Gloves fights a Nazi adversary and learns that Leda’s father is already dead—the torn page confirms it. They head to the police, but the officers, skeptical of Gloves’ claims, try to arrest him. He makes a daring exit by diving into the East River.
Gloves seeks refuge at his lawyer’s apartment, only to be ambushed by Marty’s mob, who come hoping to punish him for Joe’s murder. After a tense confrontation, Gloves persuades them of his innocence, and the two rival gangs realize they share a common enemy. They converge at the police station where Leda is being held, only to find that Hall Ebbing has bailed her out and that she’s being forced into a car.
Chasing the vehicle, Gloves and his allies discover a vast underground Nazi meeting. Two Nazis are captured and impersonated to infiltrate the room, while Gloves and Sunshine pretend to be on the inside. The explosives expert, however, is suspicious and must report on his own work, prompting Gloves and Sunshine to stall with a clever double-talk routine. The united forces of Gloves’ allies descend to break up the operation just as Ebbing tries one last gambit.
Ebbing escapes, and Pepi refuses his boss’s suicide mission. Enraged, Ebbing kills Pepi and proceeds alone toward a final act of destruction. Gloves follows to the docks, only to be shoved into a perilous motorboat packed with high explosives. Under duress, Gloves steers the vessel toward a battleship moored in New York Harbor, but he suddenly changes course and leaps into the water. The explosive-laden boat crashes into a barge and detonates, destroying Ebbing’s plan and ending the immediate threat.
Back at the police station, Gloves and Leda learn that all charges have been dropped and that the mayor will honor Gloves at city hall. Ma Donahue reappears with her trademark intuition, reporting that the milkman has disappeared and delivering the same old refrain—she “has a feeling” something else is amiss.
The film closes with a note of triumph and relief, underscored by Adolph Deutsch’s score, which threads through the tension-filled chase and the harrowing escape, leaving viewers with a sense that courage and teamwork can outpace a shadowy conspiracy even in a bustling city.
