In Soho, London, a man named Benny runs a nightclub called Ace of Clubs on behalf of its owner, Rita. Benny picks up a package inside a raincoat in the club's coatroom along with a gangster, Smiling Snyder. Snyder, however, forcefully kisses the club's star, Pinky Leroy, while she is on stage, and a sailor named Harry punches him. Snyder starts shooting at Harry, and Harry and Pinky run away with the raincoat and find the package inside shortly later. Detective-Inspector Warrilove comes to the club to investigate a jewel theft, suspecting Snyder. Snyder and an associate try to kidnap Harry to get back the package, but Harry gets away. Pinkie agrees to give Benny the parcel in exchange for Harry's safety, but Harry wants to turn it in to the police. One of the girls working at the club finds the package and finds the stolen necklace inside. Snyder gets the parcel back, but the necklace is no longer inside, as the girl is wearing it. Rita, having found out about Benny's ties to gangsters and what has been going on, tells the gangsters to get out. Warrilove notices the necklace and follows the girl wearing it, while Snyder realizes that the parcel no longer contains the necklace. He returns to the club and is caught by Warrilove, and the two couples, Harry and Pinky, and Benny and Rita, get a happy ending.
Ace of Clubs guide sections