At an Amsterdam bar called Mexico City, the narrator offers to order gin for his unnamed listener from the bartender, who speaks only Dutch. As the narrator and his listener chat, the narrator introduces himself as a former lawyer who now follows the “double” profession of “judge-penitent.” When the listener has to leave the bar, the narrator offers to walk him home—but, after walking him partway, he leaves the listener at a bridge. In parting, the narrator explains that he never crosses bridges at night to avoid people attempting suicide by drowning.
Sometime later, the narrator and listener meet again in Mexico City. The narrator explains that he used to be a very famous lawyer in Paris who took on a lot of pro bono cases. Though outwardly charitable, the narrator was egotistical and liked feeling superior to others, a feeling he managed to maintain until one fateful evening. That evening, he was walking along the quays of the Seine when, suddenly, he heard laughter whose source he couldn’t determine. Rather than finish his story, the narrator arranges to meet with the listener later, saying that he must go give legal advice to an art burglar who once committed a very famous theft.
At their next meeting, the narrator tells the listener that though he temporarily forgot about the mysterious laughter, he started avoiding the quays of the Seine and became depressed. He suggests to the visitor that they stroll outside. Outside, he comments on a shop sign decorated by the heads of enslaved Black people; inferring that the shop once belonged to a slave merchant, he argues that liberal men still tacitly condone domestic slavery and wage slavery—but they would be scandalized by such a sign. He argues that slavery is “inevitable” because everyone wants to dominate at least one other person but that society should pretend slavery doesn’t exist to protect the fragile egos of both the enslavers and the enslaved. Then he explains to the listener how, after the incident of the mysterious laughter, he began to remember incidents in his life that revealed to him his own total egotism. Finally, he reveals to the listener the most important such incident: late one night, he walked past a young woman in black on a bridge, only for her to attempt suicide by jumping into the water. After she jumped, she repeatedly cried out—but rather than try to help her, he first froze and then just kept walking.
The next day, the narrator and his listener go on a trip to Markan Island. On the boat, the narrator tells the listener that even after he realized how egotistical he was, he tried—out of egotism—to avoid that knowledge. (He claims that all people love to think themselves “innocent,” though no one is.) First, he tried to publicly condemn himself as a way of joining the side of the condemners rather than the condemned.
On the boat ride back from Markan Island, the narrator explains that after publicly condemning himself failed to make him feel better, he tried to forget his failings first through love affairs and then through mere sexual excess. At last, tired from sex and drinking, he thought he had overcome his problem—but then, on a cruise he took to celebrate his victory, he briefly and horrifyingly mistook trash in the water for a drowning person. This mistake made him realize that his failure to try to save the woman in black would haunt him forever. After the boat comes back ashore in Amsterdam, the narrator and the listener walk to the narrator’s house together. On the way, the narrator tells the listener that Jesus Christ must have been guilty of something to be crucified—for example, of surviving the Slaughter of the Innocents, in which wicked king Herod murdered many infants trying to kill the baby Jesus. He goes on to claim that while Christ only wanted to love and be loved, everyone (including but not limited to Christians) only judges rather than loving or forgiving.
When the listener comes to the narrator’s home the following day, the narrator is in bed with a fever, possibly contracted in a prison camp where he was elected pope. The narrator goes on to explain that during World War II, after the Nazis took Paris, he fled to North Africa. In North Africa, the Nazis arrested him and put him in a prison camp. There, he met a highly religious Frenchman he nicknamed “Du Guesclin.” Du Guesclin, disgusted by papal support for the fascist Spanish dictator Franco, insisted that the prisoners elect a new pope among themselves. The narrator claims that he doesn’t like to dwell on that time of his life because, after Du Guesclin died of thirst, he (the narrator) drank the water ration of another prisoner who later died—something the narrator claims he would not have done if Du Guesclin had still been living.
Abruptly, the narrator asks the listener to make sure his door is shut, and then he directs him to open the cupboard and marvel at the stolen painting therein: Van Eyck’s “The Just Judges,” a panel from a cathedral altarpiece in Ghent. He explains that a frequenter of Mexico City originally stole the painting and sold it to the bartender, who gave it to the narrator for safekeeping after the narrator explained its origins. When the listener asks why the narrator didn’t return the painting, the narrator gives a series of self-justifying responses—and then says he’s finally going to explain what exactly a “judge-penitent” is. He tells the listener that throughout their conversations, he has been acting as a “judge-penitent” through interpersonal manipulation: his purpose has been to tell stories about himself that condemn him—but in a way that subtly hold up a “mirror” to his listener as well, eventually leading the listener to confess his own sins and condemn himself. This confession will allow the narrator to feel superior to the listener despite the narrator’s knowledge of his own horribleness. Finally, the narrator demands that the listener confess what happened to him (the listener) on the quays of the Seine and call out to the woman in black to jump again. That way, the listener can actually save her this time.