The audience faces an empty stage. The company enters from the back and gets ready for a rehearsal of Pirandello's Mixing it Up. The Manager enters and calls for the second act. The Leading Man asks if he must absolutely wear a cook's cap. The Manager jumps up in rage.

The Six Characters enter from the rear. A "tenuous light" surrounds them—the "faint breath of their fantastic reality." With embarrassment, the Father explains to the angry Manager that they are in search of an author. When the Manager replies that he has no time for madmen, Father rejoins that he must know life is full of absurdities that do not need to appear plausible since they are true. To reverse this process is the madness of acting: that is, "to create credible situations, in order that they may appear true."

Father explains that as their author unjustly denied them stage-life and its immortality, they bring their drama to the company. The seductive Step-Daughter begins its elaboration: after what took place between her and Father, she cannot remain in society, and she cannot bear to witness her widowed Mother's anguish for her legitimate Son. Confused, the Manager asks for the situation and wonders how a Mother can be a widow if the Father is alive. The Step-Daughter explains that the Mother's lover—her, the Child, and Boy's father—died two months ago. Father proper once had a clerk who befriended Mother. Seeing the "mute appeal" in their eyes, he sent her off with him and took her Son. As soon as the clerk died, the family fell into poverty and, unbeknownst to Father, returned to town. Step-Daughter became a prostitute for Madame Pace. The "eternal moment" of their drama shows the Step-Daughter surprising Father as her unsuspecting client. Father then gestures to the Son, whose cruel aloofness is the hinge of the action. The Mother will re-enter the house with the outside family. Because the son will make her family feel foreign to the household, the Child will die, the Boy will meet tragedy, and Step- Daughter will flee.

The Manager takes interest. He gives the Actors a twenty-minute break and retires with the Characters to his office. After twenty minutes, the stage bell rings. The Step-Daughter emerges from the office with the Child and Boy. She laments the Child's death in the fountain and angrily forces Boy to show his revolver. If she had been in his place, she would have killed Father and Son, not herself.

Everyone returns to the stage, and the Manager orders the set prepared for rehearsal. Confused, Father wonders why the Characters themselves should not go before the public. The Manager scoffs that actors act. The Manager suddenly notices that Pace is missing. Father asks the Actresses to hang their hats and mantles on the set's clothes pegs. Lured by the articles of her trade, Pace appears from the rear. The Leading Lady denounces this "vulgar trick." Father wonders why the actors are so anxious to destroy the "magic of the stage" in the name of a "commonplace sense of truth." Pace's scene with Step-Daughter begins before Father finishes. When the actors urge them to speak more loudly, Step-Daughter replies that they cannot discuss such matters loudly—Father might overhear. Pace comes forward, saying, "Yes indeed sir, I no wanta take advantage of her." The actors erupt in laughter. The Manager finds the comic relief of her accent magnificent. Father cautiously greets the young prostitute and gallantly offers her a new hat. Step-Daughter protests that she cannot wear one as she is in mourning. The Manager interrupts, and calls the Leading Man and Lady to play the same scene. Father protests, and Step-Daughter bursts out laughing. The Manager complains that he never could rehearse with the author present.

He instructs the Father to continue. When Step-Daughter speaks of her grief, he must reply "'I understand.'" Step-Daughter interrupts: Father actually asked her to remove her frock. She refuses to let them compose a "romantic sentimental scene" out of her disgrace. Acknowledging that tomorrow the actors will do as they wish, Step-Daughter offers them the scene as it truly was. Father's "eternal moment" is the nucleus of the first act. The Manager approves and notes that the curtain will then fall. To his annoyance, the Machinist lets the curtain down in earnest.

The curtain rises, revealing new scenery: a drop, a few trees, and the portion of a fountain basin. The Step-Daughter tells the exasperated Manager that the entire action cannot take place in the garden. The Manager protests that they cannot change scenes three or four times in an act. The Leading Lady remarks that it makes the illusion easier. Father bristles at the word "illusion." Pausing, he approaches the Manager asks if he can tell him who he really is. A character can always pose this question to a man as he is always somebody while a man might be nobody. If man thinks of all his past illusions that now do not even seem to exist, perhaps his present reality is not fated to become an illusion tomorrow. The character is more real as his reality is immutable. The Manager commands Father to stop his philosophizing. He is but imitating the manner of an author he heartily detests.

The Manager prepares the scene. Step-Daughter leads Child to the fountain. "Both at the same time" the Manager commands. The Second Lady Lead and Juvenile Lead approach and study Mother and Son. The Son objects that it is impossible to live before a mirror that not only "freezes us with the image of ourselves, but throws out likeness back at us with a horrible grimace." He also protests that there was no scene between he and Mother. When Mother went to his room to speak with him, he simply went into the garden. He then saw the drowning Child in the fountain, and the Boy standing stock still like a madman, watching her. A shot rings out from behind the trees where the Boy is hidden. Some cry that the Boy is dead; others that it is only "make believe" and "pretence." "Pretence? Reality?" the Manager cries in frustration. "To hell with it all. Never in my life has such a thing happened to me. I've lost a whole day over these people, a whole day!"