A very charming and innocently frank young girl, Patty O'Neill, meets a young architect, Don Gresham, on the top of the Empire State Building. The result of this casual meeting is that she goes to his apartment, where she becomes embroiled in a whole series of amusing situations. He has invited her out to dinner, but instead she determines to cook the meal for him, and the two get along swimmingly until it turns out that Don has until the day before been more or less satisfactorily engaged to the daughter of his friend and neighbor, David Slater. Slater arrives at Don's apartment, is attracted to Patty, and when he gets too friendly Don shows unmistakable signs of purely masculine jealousy. The situation becomes increasingly involved, reaching a climax when Patty's father, an irate and Puritanical policeman, turns up and, suspecting the worst, gives Don a black eye. Ultimately, however, it turns out that Don is not the wolf that Patty's father imagined, and at the very end, when the scene reverts to the top of the Empire State Building, all ends satisfactorily.
Had an immensely successful run on Broadway and the road. "…turned out to be the light-hearted comedy everyone…had been waiting for." —NY Times. "Nothing but fun. THE MOON IS BLUE is a happy sign of spring—jaunty as a fine Easter bonnet…I came away from the theater feeling young and gay." —NY News.