The setting is a study in Portland Place, London. Onstage is Roebuck Ramsden, a rather elderly man of affluence and affairs. Octavius Robinson, a young poet, is announced by the maid. He appears dressed in an elegant suit of mourning. As Ramsden consoles him, the audience learns that Octavius' benefactor and friend, Mr. Whitefield, is dead. Ramsden is confident that he will be the one who will serve as guardian of Whitefield's daughters, Ann and Rhoda, and he expresses his hope that Ann and Octavius will marry. Octavius can think of nothing which would make him happier. As they discuss this matter, Ramsden warns the young poet against the latter's friend, John Tanner, author of the notorious Revolutionist's Handbook. Ramsden prides himself on being an advanced thinker and liberal but regards Tanner as an immoral person. If Ramsden indeed is to be the guardian of the lovely Ann, he will see to it that Tanner is kept away from her.
At this point, the object of Ramsden's disapproval appears. Jack Tanner, an attractive and obviously superior young man, is in a state of near-panic. As he excitedly informs Ramsden, both he and the latter have been appointed by Whitefield's will to act as Ann's guardians. Ironically, Tanner, to whom Ramsden is hopelessly old-fashioned, was responsible for his own appointment, one which he dreads. He had advised Mr. Whitefield to team Ramsden up with a younger man, not dreaming that he would be White-field's choice. He pleads with Ramsden to get him out of this predicament, arguing that Ann is anything but the weak, dutiful young woman. He sees her as willful and hypocritical and declares that she will "commit every crime a respectable woman can." Ramsden himself states emphatically that he will refuse to act as guardian with Tanner. But the younger man prophesies that neither one of them will escape the obligations which have been forced upon them. Octavius is as appalled at Tanner's unflattering description of Ann as an unscrupulous siren as Ramsden is at Tanner's political views. To him she is a goddess, nor can anything that Tanner says convince him that she is not divine. For the naive Octavius, she is the "reality of romance."
Now Ann makes her appearance. Shaw describes her as "perfectly ladylike, graceful, and comely, with ensnaring eyes and hair." What sets her apart from other beautiful women is her abundant vitality. With her is Mrs. Whitefield, her mother, a little woman certainly devoid of such vitality, one who wears an expression of "muddled shrewdness." Playing her role of the dutiful and helpless daughter, Ann listens to Ramsden, who tells her that Tanner and he have been named as joint guardians and trustees of the late Mr. Whitefield's two daughters. Tanner's prophesy is soon justified. Ann will not violate her father's will; both Ramsden, whom she calls "Granny," and Jack must serve.
Ramsden, who had left the stage while Octavius and Jack express their markedly contrasting views of Ann, returns with "terrible news." Octavius' sister Violet is about to become an unmarried mother. All but Tanner are greatly shocked. He declares that the girl should be congratulated on "the fulfillment of her highest purpose and greatest function — to increase, multiply, and replenish the earth." It is Ramsden especially who expresses the conventional attitude: Violet is the victim of "a rascal . . . a libertine, a villain worse than a murderer" who is in their very midst! When he expresses his suspicions of Tanner, whom he describes as "a man of notoriously loose principles," Tanner adroitly points out that suspicion clings to Ramsden as well.
For the first time alone together on the stage, Ann and Jack converse. The audience learns that the two had known each other since childhood and that Jack had once declared his love for her. She does admit that once, when he had pretended to be in love with another girl, she had violated Jack's confidence; she had told the girl that Jack had informed her of the attachment. Tanner states that, as a result of his experience, he has come to believe moral passion to be the only real passion; no romance for him now. The entire episode is replete with interesting Shavian ideas which will be discussed later. What especially is made clear is that Ann indeed is the active one in the love game. As Tanner says, "I never feel safe with you: there is a devilish charm — or no: a subtle interest."
Ramsden and Octavius come back with Miss Ramsden, a hard-headed spinster who is determined that Violet must leave the house at once since she apparently wished to meet her betrayer again. Violet herself enters. She is quite self-possessed and obviously impenitent. When Tanner eloquently voices his approval of her, she turns upon him and vehemently repudiates his compliments. In so doing, Violet is forced to reveal the fact that she has been secretly married and is not a fallen woman at all.