ACT I Governesses are busy looking after the children entrusted to their care. Checkalinsky and Tsurin discuss the behavior of Herman, a morose outsider who sits brooding in the casino without taking part in the card games. Herman tells his friend Tomsky the reason for his anguish: he is in love with a woman whose name he does not even know, but whom he can never marry because of her noble birth. When Yeletsky introduces his fiancée Lisa, who is accompanies by the Countess, Herman recognizes Lisa as his as yet unknown love. The two women are bewildered by Herman’s strange, yet passionate gaze. Tomsky explains that the Countess was known for her exquisite beauty in her youth. After losing at the card tables, the Countess discovered the secret of the three lucky cards which enabled her to win back her fortune. But the price was high: a rendezvous with a certain Count Saint-German. However, the Countess was also told that one day a man driven by passion and love would force her to reveal the secret of the three cards, and that he would also be the cause of her death. Herman is fascinated by the tale and resolves to solve the riddle, hoping to win both his love and his fortune. On the evening of Lisa’s engagement, a group of her close friends have gathered to bid her farewell. Pauline sings Lisa’s wistful love song. That night, Lisa confesses her love for Herman. When he enters her room, Herman and Lisa reveal their passion for one another. Awoken by the noise, the Countess appears and gives Lisa a stern warning. Herman’s interest in the mysterious Countess is aroused once more.
ACT II Yeletzky is celebrating his engagement to Lisa at the palace of the Countess. However, he is disconcerted by Lisa’s coldness towards him. Once again he confesses his love to her. Lisa furtively slips Herman the key to a secret door, instructing him to come to her bedroom that night. However, to do so he must pass the room of the Countess. The Countess is immersed in her memories until she notices Herman. She realizes that this is the man driven by love to discover her secret of the three cards. And indeed, he begs her to reveal her secret to him. However, the Countess dies in the course of this tumultuous encounter. At this moment, Lisa appears and curses Herman. Having failed to find out about the three cards, Herman is despondent.
ACT III Herman is reading a letter from Lisa in which she asks him to talk things over with her. At the funeral of the Countess, Herman breaks down at the sight of her coffin. He hears the voice of the dead Countess naming the three cards: the three, the seven, and the ace. Lisa is waiting for Herman. When he finally arrives, to her great displeasure, he is still obsessed only by his passion for the cards. She sees only one way out of this situation: death. At the casino, Yeletzki is bent on taking his revenge on Herman because of Lisa. Herman finally tries his luck at the card table, winning a fabulous sum of money with the first two cards. He then stakes his entire fortune on the third and final game. However, his third card is not the ace as he expected, but the Queen of Spades. Herman loses not only the game, but also his life.