Act 1. Ramsden and Octavius discuss Ann, whom Octavius wants to marry, and John Tanner, Octavius’s friend and the author of The Revolutionist’s Handbook. Tanner enters, protesting that he and Ramsden had been named Ann’s guardians in her father’s will. Ramsden does not wish to serve with Tanner and Tanner does not wish to serve at all, but Ann, entering with her mother, refuses to dispense with either guardian. Tanner states that Ann will do what she likes in any case. When they are left alone, Tanner and Octavius discuss Ann; Tanner predicts that she will eventually marry Octavius. Ann and Ramsden return with the news that Octavius’s unmarried sister, Violet, is pregnant. Ramsden and Octavius leave, and Tanner and Ann engage in a long discussion about their relations when younger. Tanner asserts that he has grown up and no longer plays romantic games; now he is concerned to break creeds and demolish ideals. When Violet comes in, Tanner approves of her conduct, but Violet says that she is, in fact, married, but she refuses to name the man.

Act 2. While Henry Straker, the chauffeur, is working on Tanner’s car, Octavius announces that he has proposed to Ann and has been put off. Ann comes in and discusses why she has forbidden her sister to take a drive with Tanner. Tanner says he is off on a trip to Algiers and jestingly asks Ann if she wishes to accompany him. To his horror, she accepts. Ramsden, Octavius, Mrs. Whitefield, and Hector Malone, a rich young American, enter, and Hector says that he will take Violet in his car. All except Hector leave for a walk, whereupon Violet returns and kisses Hector. They have been keeping their marriage secret because Hector’s rich father wants him to marry a British aristocrat. After they leave, Straker and Tanner come back discussing Ann; Straker insists that it is Tanner whom Ann is pursuing. At that, Tanner panics and orders Straker to get ready to set off on a trip to North Africa.

Act 3. In the Sierra Nevada of southern Spain, a group of brigands led by Mendoza captures Straker and Tanner for ransom. Mendoza reveals that he is a former waiter at the Savoy Hotel and hopelessly in love with Louisa, who turns out to be Straker’s sister. Tanner tries to talk Mendoza out of his obsession with Louisa. While they sleep, Don Juan and the Old Woman appear in Hell. The woman, who has just died and protests that she does not belong there, turns into a young Doña Ana, a former beloved of Don Juan. She looks much like Ann Whitefield. The commander, Doña Ana’s father, who had once been slain by Don Juan, appears on a visit from Heaven, after which the Devil appears. The commander, who resembles Roebuck Ramsden, wants to live in Hell because Heaven is so dull. The Devil, the commander, and Don Juan explain at length to Doña Ana the true nature of Heaven and Hell. Hell is the home of the unreal and of the seekers for happiness, a place of playing and pretending; Heaven is a place of contemplation, where live the masters of reality, helping the struggle of the Life Force upward. Then follows a long discussion of the Life Force and of its sidetracks in life on Earth.

Don Juan leaves for Heaven. The commander leaves with the Devil and mentions Friedrich Nietzsche’s Superman. Doña Ana asks where she can find the Superman; the Devil says he has not yet been created. Doña Ana is left on a darkening stage, crying out for a father for the Superman. As the scene returns to the Sierra, Ann, Hector, Ramsden, Violet, and Octavius appear, accompanied by soldiers; the brigands are captured but Tanner saves them from arrest by claiming that they are his escorts.

Act 4. In the garden of a villa in Granada, Violet and Hector’s father, who has intercepted a note from Violet to Hector, discusses Hector; Malone threatens to disinherit Hector if he marries Violet, and when Hector enters, they quarrel. When it becomes known that Violet and Hector are already married, Hector’s father capitulates. Ann tells Octavius that she cannot live up to his ideal of her and that her mother wants her to marry Tanner. Mrs. Whitefield tells Tanner that she has not influenced Ann but does think it would be a good idea because Tanner could handle Ann. When Tanner and Ann are left alone, Tanner protests that he does not want to marry Ann but that everyone else seems to take it for granted that he will. The Life Force urges Tanner on, and he takes Ann, who fainted, in his arms. Everyone returns to find that Tanner has yielded.