On a ship an entertainer is wooed by a jewel thief while her brother is compelled to help her former lover, who gets murdered.
On a cruise Chad Denby (Jack Benny) hosts a radio program. Jimmy Brett (Gene Raymond) got his crime partner Shorty (Sid Silvers) a job on the ship and asks him for money. Jimmy kisses Sally Marsh (Nancy Carroll) along with her friends. Her brother Ned Marsh (Carlyle Moore Jr.) is worried that Lee Lothar (Sidney Blackmer) is on board. Lothar invites Jimmy to play poker. Jimmy gets in a shuffle board game with Sally, Chad, and Inspector McKinney (Robert Elliott). Jimmy picks McKinney's wallet out of his pocket. In the poker game Lothar and Jack Summers (Sam Hardy) let Jimmy win at first; but Shorty comes to tell Jimmy his mother is sick, and Jimmy wins $1600. Lothar lures Sally into his room to be photographed and tries to kiss her; but she doesn't like him anymore. Anya Rosson (Shirley Grey) comes in, kisses Lothar, and slaps him. Chad tells Jimmy he needs Sally for rehearsal; but Jimmy tells Sally he wants to see her all the time.
The show presents "Rock and Roll" and "If I Had a Million Dollars." Jimmy goes to Anya's cabin and steals her bracelet. McKinney sees him in the hall. Chad, Sally, and others do a radio show called "Grind Hotel" satirizing Garbo's movie. Mitzi sings "Oh, Leo." Anya says her bracelet was stolen. Jimmy leaves it for Shorty, and McKinney says he is on vacation. Sally tells Jimmy to forget romance. McKinney searches Jimmy, and Jimmy gives the bracelet to Shorty. At the pool Jimmy talks with Anya and then Sally. Shorty is seen with the bracelet, runs, jumps in the pool, and passes it to Jimmy underwater. Sally objects to Ned helping Lothar, but Ned tells her he owes Lothar money. Lothar and Summers ask to play poker and then demand the $1600 from Jimmy, who refuses with contempt. Shorty cheats a drunk at dice. Sally asks Lothar to give Ned's check back, and he promises to do so after the show. Chad tells Lothar to leave Sally alone. The show performs "It Was Sweet of You."
Lothar hits Ned before Ned can hit him. Ned asks Chad for a gun. Jimmy walks Sally to her cabin and kisses her. Lothar is shot while approaching Sally. McKinney questions Sally, Jimmy, Ned, and others. He found Chad's gun in Ned's room. However, it is all quickly resolved after the jealous Herbert Rossen shoots Anya from the window and admits he killed Lothar too. Chad tells Jimmy to be on the level because of Sally. McKinney picks the bracelet from Jimmy's pocket and says he will recommend probation. In the final scene Jimmy and Sally kiss.
This crime story and murder mystery is spiced with music and humor - what the idle rich and those who prey upon them do crossing the Atlantic.