Death and the Maiden tells the story of Paulina Salas, her husband Gerardo Escobar, and Dr. Roberto Miranda, all citizens in an unnamed country that is recovering from the after-effects of a violent dictatorship. When Gerardo's car breaks down one night, a kindly stranger named Roberto Miranda offers to drive Gerardo back to his beach house.
A grateful Gerardo offers Roberto a room for the night, but after hearing Roberto's voice, Gerardo's wife Paulina becomes convinced that their houseguest is the doctor who raped and tortured her after she was abducted by the secret police fifteen years earlier. Of all of her torturers, this doctor was the cruelest because of his occasional intimations of kindness and his propensity for playing Schubert's Death and the Maiden while subjecting Paulina to sexual and physical torture.
Determined to mete out her own brand of justice, Paulina surprises Roberto in the middle of the night, kidnapping him and announcing to Gerardo that she is going to put Roberto on trial for the crimes she believes he has committed. Gerardo, however, has recently appointed been to an Investigating Commission that the country's new democracy has set up to examine crimes of the dictatorship, and he is horrified by Paulina's attempt at vigilante justice. He instinctually tries to convince her to let Roberto go. Gerardo is worried that Paulina's actions will threaten both his own position in the government as well as the new democracy's ability to successfully pursue justice for its citizens. Although Gerardo tries to physically force Paulina to free Roberto, she maintains a firm hold on her gun and threatens to shoot Roberto and herself unless Gerardo backs off.
Roberto vehemently proclaims his innocence, claiming to have never met Paulina before. Meanwhile, Paulina offers Gerardo a compromise: if Roberto formally confesses to his crimes, she will let him go. Roberto is appalled by this idea, but Gerardo manages to convince him that a confession, even if it is false, will be the only way to save his life.
Gerardo persuades Paulina to record a testimony of her abduction and torture so that he can secretly pass the details along to Roberto, who in turn can make an accurate "confession." In the meantime, a major rift in Gerardo and Paulina's relationship comes to light; after being freed from captivity, Paulina went straight to Gerardo's home, only to find him with another woman. Although she forgave him at the time, it is clear that Paulina still bears great anger towards her husband for his betrayal.
Meanwhile, Roberto records a written and verbal "confession" based on the testimony that Gerardo has gotten from Paulina. Gerardo urges his wife to hold up her end of the bargain and free Roberto. She agrees and then encourages Gerardo to go fetch Roberto's car (which Paulina hid earlier).
As soon as Gerardo leaves, Paulina turns on Roberto, announcing her intent to kill him. Although she has "confessed," she is not satisfied - she does not believe that Roberto truly regrets his actions. Furthermore, Paulina points out that in telling her story to Gerardo, she deliberately added some inaccuracies to see if Roberto would unconsciously correct them, which he did, leaving her fully convinced of his guilt.
Roberto maintains his innocence until the end, swearing that his confession was fake, and begs Paulina to spare his life and stop the cycle of violence. Furious, she demands to know why it must always be people like her - the victims - who have to restrain themselves. As she holds the gun to Roberto's head, a huge mirror descends on the stage, forcing the audience members to stare at themselves and each other instead of witnessing the play's climax.
A few months later, Paulina and Gerardo are at a concert. While Gerardo speaks happily to other audience members about the success of his Investigating Commission, Paulina is confronted by the image of Roberto - which Dorfman asks the audience to interpret as either real or in her head. As Schubert's "Death and the Maiden" begins to play, Paulina and Roberto stare at each other and the lights fade.