As passengers board the cruise ship San Capador , its captain, Helquist, tells a group of reporters how much he hates the sea, and that he only became a sailor to escape his father. He also informs the reporters that, in the case of an accident, he plans to be the first man in a lifeboat, having no intentions of "going down with the ship." Newspaperman Steve Bramley arrives at the dock, delivered there by his fiancée, Gerta Klangi. Steve is leaving Hollywood, where he has failed as a screenwriter, to go back to New York, in the hope of both writing a book, and giving up the bottle. Once aboard the ship, Steve runs into his old drinking buddy, Layton, the ship's chief steward. They are soon joined by another old friend, private detective Junius P. Schulte, who is aboard the ship in search of $250,000 in stolen bonds. Just after the ship leaves the dock, the pilot ship pulls alongside, and notorious crook Danny Checkett boards the cruise ship, under the name "Fairaday." He is immediately greeted by Schulte, who asks him to hand over the bonds. Danny declares his innocence, and their game of "hide-and-seek" begins. Also aboard the cruise ship are Mr. and Mrs. Jeddock, a seemingly distinguished couple; Mrs. Yolanda Magruder, a feisty rich widow; General Salazaro, a revolutionary; and Bostonian Janet Grayson, a librarian on vacation. At dinner that night, Danny and Schulte both vie for Janet's attention. Afterward, Steve goes back to his room, where he finds a phonograph record of Gerta, in which she proclaims her love and belief in him. Despite her encouragement, Steve immediately "falls off the wagon," and soon becomes a close friend of the head bartender. When Steve sees Mrs. Jeddock for the first time, he recognizes her as an old prostitute he knew under the name "Goldie." Mr. Jeddock is so upset by this that he attacks Steve, but the writer, though intoxicated, still beats the hapless husband to the punch. Later, when Danny is alone with Janet, their true relationship is disclosed: they are actually accomplices, engaged to be married. While Danny is pleased that Janet has attracted the attention of Schulte, he, in turn, is being pursued by the elder Mrs. Magruder. Janet, thinking that Schulte is completely taken by her, hides the stolen bonds in the detective's cabin. Schulte, however, is on to her, knowing that her real name is Blanche Ditworthy, and is otherwise known as "Michigan Red." Layton discovers the truth about Danny and Janet, and blackmails the crooks to keep their secret from Schulte. After four days at sea, Salazaro is greeted with a hero's welcome by his old friend Juan Gilboa when the ship docks in his country. The other passengers are shocked to learn, a bit later, that Salazaro has been executed by a firing squad, as his revolutionary group had been defeated prior to his arrival. Back at sea, Schulte proposes marriage to Janet, and she accepts as part of her ruse. As Schulte announces their engagement, the band plays "The Wedding March," just as the Jeddock's arrive in the dining room. Mr. Jeddock explodes at the group, thinking that the song is a snide comment on his wife's past, and is taken away by the ship's crew, who throw him in the brig. Mrs. Jeddock then attempts suicide by jumping off the ship, but both Danny and Schulte jump to her rescue. Janet goes to Schulte to tell him the truth, only to discover that he knows all, having found the bonds, yet still wishes to marry her. As the ship arrives in New York, Mr. and Mrs. Jeddock are reunited in the captain's quarters, where Mrs. Jeddock gives her husband a piece of her mind, as well as part of a blackjack. At the dock, Danny, who realizes that he has lost both Janet and the bonds, renews his acquaintance with the rich Mrs. Magruder, whom, he learns, is worth $7,000,000. Schulte gives his business card to Janet, and tells her to meet him there, which she does. Finally, Steve leaves the ship, in no better condition than he boarded, only to be met by Gerta. Though she realizes he has lost yet another battle with the bottle, she accepts him back in her arms, and they drive away.