The main action takes place on a luxury liner sailing from New York to Southampton. But first we come to a preliminary scene in a smart New York bar. Reno Sweeney, a night-club entertainer, on the eve of leaving for Europe, expresses her sentiments for Billy Crocker in "I Get a Kick Out of You".

Once she boards the liner she discovers to her delight that Billy is also a passenger, though an unlisted one. He had come to bid Reno "bon voyage" when he comes upon his one-time fiancée, Hope Harcourt, en route to England to marry Sir Evelyn Oakleigh. His former love for Hope suddenly revived, Billy impetuously decides to stay on the ship when it sets sail, even though he possesses neither a passport nor a ticket. He manages to get both from a pathetic-looking, broken-voiced little man who is Public Enemy No. 13 fleeing from the police disguised as a clergyman, Reverend Dr. Moon. One of Moon's confederates had failed to show up at sailing time, and Billy can use his ticket and passport if he is willing to travel in disguise. Once the ship leaves harbour, Billy is able from time to time to emerge from his disguise--once to be romantic with Hope ("All Through the Night"); another time to exchange saucy compliments with Reno ("You're the Top"). When Moon's real identity is revealed he is confined to the brig by the ship's captain. The latter is suddenly inspired to hold an improvised revival meeting with Moon as his main penitent. After Moon inspires some of the passengers to confess their sins, Reno carries the revival meeting to a stirring climax with "Blow, Gabriel, Blow".

All the principals come to Oakleigh's home in England, where Hope and Sir Evelyn are to get married. The prospect of marriage pleases neither of them, since their union had been an arrangement of convenience to save Bailey Products, a floundering business establishment. But Hope and Sir Evelyn soon learn that Bailey Products is not bankrupt at all; that, indeed, a buyer stands ready to purchase it for several million dollars. Thus Hope and Evelyn are free to go their separate ways. Hope returns to Billy, while Sir Evelyn and Reno discover each other. Meanwhile, word has come down from Washington, D.C., that "Moon" is free to go as he pleases: the police are not interested in him at all, since he is as harmless as a cream-puff. The sudden loss of status upsets the little man to no end. "Sometimes," he whines, "I just can't understand this administration in Washington!"

This was the first time that Lindsay and Crouse worked together, initiating a playwriting partnership that was destined to become one of the most successful in the American theatre, and built on the solid foundation of one of the outstanding musical comedies of the 1930s