At the Brooklyn Navy Yard, Harry Quirt tells his buddies that he is quitting the Marines to become a comedian. After he loses a ten dollar bet to his rival, Jim Flagg, who accuses him of trying to steal every girl he has chased, Quirt bets him double-or-nothing on a roll of dice and wins when Flagg insists that they use dice belonging to Olsen, a not-too-intelligent Swede. Unknown to Flagg, Olsen has just received the dice as a gift from Quirt. Three years later, Olsen, while driving Flagg's limousine, knocks down Quirt as he tries to cross the street. As Flagg talks with their buddy, ex-Marine Joe Eagan, who is now a policeman, Quirt gets into the limo and flirts with Flagg's two women friends, Hortense Rhinelander and Lily Reed. They go to one of the twenty-eight clubs Flagg now owns, and Quirt shows Flagg a badge that identifies himself as an investigator for the Federal Prohibition Service. After Quirt accepts a $10,000 payoff, he exits with the girls and leaves Flagg his badge, which was made by a novelty company. The girls take Quirt to a poker game, where he is fleeced of all his money by Trigger Thorne, who is in cahoots with Hortense. Quirt, however, impersonates a special investigator from the district attorney and "allows" Thorne to pay him twice the amount he lost to avoid arrest. Meanwhile, Flagg finds the crew on his rum-running boat terrorized by a knife-wielding female stowaway from South America. Afraid of the jail sentence he could receive for smuggling her in, Flagg locks her in a closet. The woman, who calls herself "Pepper," entices Olsen to hide her in a gunnysack and carry her to shore. At Flagg's home, Pepper locks Olsen in a closet and then confronts Flagg. When he tries to put her out, she takes off her skirt, then throws her underwear in his face and removes her brassiere. She dares him to put her out like that and then crawls into his bed. As she wriggles, he warms to her, but she escapes his grasp just as his henchmen bring in Quirt. After Pepper tells Quirt that Flagg smuggled her in, Quirt threatens to turn him in unless he pays him $5,000. Thorne then visits, and while he talks to Flagg, Pepper romances Quirt and begs him to protect her. They escape in Flagg's car, and when Flagg pursues them in Thorne's car, Quirt convinces a motorcycle cop that Flagg stole his wallet, and Flagg is arrested. A month later, Flagg attends the gala opening of Quirt's new club where Pepper, billed as "Hot Pepper," is the singing attraction. Eagan, now a detective, warns Quirt that the club is on a list to be raided. Flagg begins a flirtation with Pepper, but Quirt then proposes to Pepper that they go to South America and open a nightclub there. The idea is agreeable to Pepper, but she wants to bring Flagg. After Flagg and Quirt toss a coin to see who gets to marry her, Quirt wins, using a two-headed coin, but Pepper becomes very indignant that they don't fight for her. Thorne then arrives with his gang, and when they start to rough Quirt up, Flagg begins a brawl. They wreck the club, and after the police break up the fight, Quirt thanks Flagg and offers to sell him the club, but Flagg knows about the planned raid. Flagg then asks Pepper to choose between them, but she leaves for South America where, she says, men don't toss a coin for a woman's heart. Because they know that bootlegging will soon be over, Quirt and Flagg decide to go someplace else to find excitement. In China, during a battle, Flagg, the new commanding officer, tries in vain to communicate with his Chinese troops. The general who arrives for inspection turns out to be Quirt, who explains that he learned the language in night school with two Chinese girls, one of whom wears a Distinguished Service medal manufactured by a novelty company. Quirt and Flagg then harangue each other as their troops march off.