When florist Johnny Allegro makes a delivery at the Los Angeles hotel in which his shop is located, an attractive blonde greets him noisily and then quietly begs him to pretend that he knows her. Curious, Johnny goes with her to the hotel bar. She introduces herself as Glenda Chapman and tells him a story of great intrigue. Although Johnny immediately sees through her story, he agrees to help her dodge the police detective waiting in the lobby. Over the following days, Johnny becomes romantically involved with Glenda. One night, treasury agent Schultzy visits Johnny and confronts him with his past as a gangster and fugitive from Sing Sing prison. Because Johnny risked his life in the O.S.S. after his escape, Schultzy offers him a chance to redeem himself by gathering information about Glenda. When Johnny meets Glenda that evening, she tells him that she is leaving but will not tell him anything else. Johnny agrees to help her leave the hotel secretly, but when they arrive in the basement, a policeman is waiting, and Johnny shoots him. He then insists that Glenda take him with her to protect him from the police. Glenda reluctantly agrees, not knowing that the killing was faked, and that Johnny is working undercover. Johnny and Glenda fly to Florida in a private plane and then take a boat to an unidentified island. On the island, Johnny learns that Glenda is married to Morgan Vallin, a mysterious man who believes that the bow and arrow is a better weapon than a gun. Suspicious of Johnny, Vallin forces him to hand over his gun. Realizing that his deception will be revealed if Vallin discovers the gun is loaded with blanks, Johnny tries unsuccessfully to retrieve it. In the morning, Johnny explores the island and sees the arrival of two men, later identified as Pelham Vetch and Grote. In the afternoon, Vallin takes Johnny and Glenda to the mainland for the races. There, Vallin gives Johnny a package to deliver, and Johnny takes the opportunity to get a message to Schultzy. Later, while Glenda and Johnny have dinner together, he pretends to have a malaria attack. At the hospital, Johnny meets secretly with Schultzy, who tells Johnny that Vallin works for a group which plans to flood the West Coast with five million dollars in counterfeit money. He asks Johnny to find out where the money is hidden. Back at the island, Glenda makes a pass at Johnny, which is interrupted by Vallin. Vallin then threatens Johnny, warning him that he is a bad loser. Late that night, Johnny sneaks to the boat and calls Schultzy on the radio. Using that information, the Coast Guard moves in to surround the island. Vetch and Grote spot the ships and accuse Vallin of treason. Eavesdropping on their argument, Johnny learns that the counterfeit money is hidden on the island. Then Vallin kills the two gangsters and prepares to leave the island, and Johnny again signals the Coast Guard. This time, Glenda finds him and divulges her wish to leave Vallin and start fresh with him. She then leads him to the cave in which the money is hidden. Meanwhile, Vallin discovers the blanks in Johnny's gun and hurries to the cave, where Johnny is fighting with one of Vallin's henchmen. Armed with a bow and arrows, Vallin stalks Johnny, but Glenda prevents the murder. Johnny and Vallin then grapple, and in the ensuing fight, Vallin falls to his death. Glenda and Johnny are rescued by the Coast Guard and are promised light sentences for their help with Vallin.