Dan O'Farrell and Barry Keith-Trimble, two actors, prepare for the opening night of "Laughter", a new play written by Dan, by getting drunk at the Lambs Club. By the time they go on stage, they are still not sober, and end up brawling and falling in the orchestra pit. They continue drinking, returning to the club and laughing hysterically until they are suspended. Dan simultaneously learns that his wife, actress Alyce Martelle, is pregnant and that she has left him for ruining his play. Twenty years later, Dan is still sitting at a table in the club, his ambition deadened by the knowledge of his own failure. He is supported by Barry, who has married into wealth and retired. In the interval, a former Lambs Club waiter, Michael Fordkin, now known as J. Neville Prime, has become the leading Broadway producer, employing Sammy Kayn, Dan's former stagehand. Dan faints upon learning of the existence of his daughter Marie Alyce, who was given over to a French convent upon the death of her mother in childbirth. Dan nervously meets Marie at the train station, but is supported by Sammy, Neville and especially Barry, who rents a lavish room for her. Marie, who is the image of her mother, is soon asked by Dan to recite the lines Alyce was to have said in "Laughter". Believing he is an unworthy father, Dan urges Marie to take advantage of an opportunity to study art in Paris. Dan orders Barry to put Marie on the ship to France, but is surprised to find them waiting in his small apartment later that night. Marie tells Dan, who has wanted to die for fifteen years, that Alyce would have forgiven him. He suddenly decides to re-stage "Laughter" with the original cast, with Marie substituting for Alyce in the part of Toni. After long rehearsals, Dan becomes ill, but continues in his role of the clown. Marie convinces him to change the play to have a happy ending, with Toni reuniting with the clown, rather than have the clown commit suicide over her departure. The play is an enormous success by the conclusion of the second act. After Dan's final scene, he has a heart attack, believes he hears Alyce, and goes to his dressing room to be with her. As the play ends, Dan dies, but Alyce lives on in Marie as Dan's friends drink to the fulfillment of his hopes.
