Maurice Bendrix, who is both the protagonist and narrator of The End of the Affair, notes that this story is “a record of hate far more than of love.” One cold and rainy night, Bendrix walks out of his apartment with the intention of going to a nearby pub. He catches sight of Henry Miles standing alone in the rain, and even though he hates Henry, Bendrix greets him. Henry, on the other hand, appears enthusiastic about seeing Bendrix, noting that he hasn’t seen Bendrix in quite some time and implying that any hatred between the two is entirely one-sided. Bendrix asks Henry about his wife, Sarah, simply because it would seem unusual not to. Bendrix thinks to himself that he would be thrilled to hear that Sarah is unhappy and sick because learning that she is suffering would diminish his own suffering. Henry tells Bendrix that Sarah has gone out for the night. Bendrix invites Henry to accompany him to the pub for a drink, Henry agrees, and they walk to the nearest one.
At the pub, Bendrix and Henry each order a rum, and Bendrix thinks back through the years to remember how he originally got to know Henry and Sarah. In 1939, Bendrix had been writing a novel that featured a civil servant as the protagonist. He invited Sarah out to lunch to ask her questions about Henry, who was a secretary at the Ministry of Home Security. From there, they began a friendship. Eventually, Bendrix told Sarah about his book and that he was using Henry as source material for foolish character who was the book’s comic relief. Sarah, who was fiercely loyal of Henry immediately hated the book. From then on, Bendrix would purposely ask Sarah questions about Henry to tease her even though it made her cry.
Back in the present, Henry tells Bendrix that he is “worried” about Sarah. Bendrix asks Henry if Sarah is ill, but Henry tells him that he doesn’t think so. Henry invites Bendrix back to his house to talk somewhere quieter and more private. Once there, Henry shows a Bendrix a letter with a recommendation for a “discreet” private detective, implying that he has suspicions about Sarah’s faithfulness and has looked into hiring a private detective to follow her. When Bendrix offers to save Henry the embarrassment by going to the detective, Mr. Savage, himself, Henry insists that it can’t be done and burns the paper with Mr. Savage’s address. Just then, they hear Sarah come inside. Henry tells Sarah she’ll die of a cold because she’s soaked through from the rain. In a narrated aside, Bendrix wonders if anything in his and Henry’s feelings of “distrust, and hate” would have changed if they’d known just how true Henry’s statement was.
Several days later, Bendrix goes to see Mr. Savage. During their interview, Bendrix tells Mr. Savage that he and Sarah had an affair but haven’t been together since June 1944, about two years before the current time. When Mr. Savage expresses surprise, Bendrix asks, “Can’t one love or hate […] as long as that?” Mr. Savage notes that jealousy is “the mark of true love” and arranges to have a man follow Sarah and provide Bendrix with weekly reports of her whereabouts.
Back at home, Sarah calls Bendrix and asks him to meet her for lunch because she has something to talk to him about, and Bendrix agrees. At a restaurant called Rules, which they used to frequent together, Sarah tells Bendrix that she’s worried Henry is lonely and asks Bendrix to talk to him every once in a while. Bendrix expresses surprise that Henry is lonely with Sarah around, and she reminds Bendrix that Henry hasn’t “really noticed [her]” for years. Bendrix pays the bill and they leave the restaurant, stopping at the grating where they shared their first kiss years before. Bendrix moves towards Sarah as if he might kiss her again, but just then she has a coughing fit—the second one during their afternoon together. Bendrix coldly tells her to get her cough checked out, and they go their separate ways.
Back at home, Bendrix thinks about his past relationship with Sarah. Throughout much of their relationship, Bendrix had been able to maintain his usual writing schedule. Once he realized how much they were arguing and that their relationship was doomed, however, Bendrix struggled to write anything. Bendrix’s landlady interrupts his thoughts, informing him that a man named Mr. Parkis wants to talk to him. When he enters, Mr. Parkis introduces himself as “Mr. Savage’s man,” there to provide the Bendrix with first report. As he reads the report, Bendrix realizes that Mr. Parkis had been watching him and Sarah have lunch, although Mr. Parkis hadn’t recognized Bendrix. When Bendrix tells him about it, Mr. Parkis feels humiliated and worries about what he’ll say to his son, Lance, about it. Even though Bendrix tells Mr. Parkis to just tell a different story to explain the mistake, Mr. Parkis insists on admitting the mistake to Lance. As Mr. Parkis leaves, Bendrix realizes that he was—for once—briefly distracted from thoughts of himself and Sarah because he was so interested in Mr. Parkis’s dilemma.
Alone, Bendrix thinks about the first days of his affair with Sarah. Shortly after their first kiss, they had gone to see a movie that was based on one of Bendrix’s books together. After that, they got lunch at Rules before deciding to go to a hotel together. After awkwardly having sex for the first time, they went back to Sarah’s house and held each other in the parlor while Henry worked in another room. When Bendrix mentioned that Henry could walk in on them without warning, Sarah told him there was a squeaky stair that would alert Henry’s presence. Later, when Sarah walked Bendrix to the door, she told him that it would be better if she called him rather than vice versa. This forethought made Bendrix realize that Sarah had carried out other affairs in the past. A short time later, Bendrix went to Sarah’s house to see her while Henry was sick in bed, and they had sex on the floor of her parlor. When Sarah climaxed, she told Bendrix that Henry had never gotten her to do so in their 10-year relationship. This explained why Sarah had turned to extramarital affairs: sexual satisfaction and fulfillment.
Back in the present, Mr. Parkis sends Bendrix a report that he had followed Sarah to a private residence on Cedar Road, where she appears to spend a lot of her time. Mr. Parkis also sends a scrap of a love letter, in which Sarah had written, “I want to abandon everything, everybody but you”—but it’s unclear who “you” is. After reading the letter, Bendrix enters a downward spiral of jealousy and remembers all the arguments he and Sarah had about his jealous nature during their relationship. A few days later, Bendrix receives another report about Sarah going to the same address on Cedar Road. For Bendrix, this seems like confirmation that Sarah is romantically involved with someone else, and he writes to Henry telling him that he has important information to share. When he and Henry meet for lunch a short time later, Bendrix reveals that he hired Mr. Savage and, as a result, has evidence that Sarah is having an affair. When Bendrix tries to give Henry the reports and evidence, Henry throws them into the fire instead of reading them and then storms out of the building. When Bendrix catches up with Henry, Henry asks him if he and Sarah had also had an affair. Bendrix confirms that they did and explains that Sarah has affairs because Henry is “a bore and a fool.”
Henry asks Bendrix why the affair between him and Sarah ended, and Bendrix says it’s because their love simply reached its conclusion. Bendrix thinks privately about how his affair with Sarah really ended: the final night of their relationship coincided with the first night of the V1 bombings in London in 1944, shortly before the end of World War II. Bendrix and Sarah were in bed together when they heard the air raid start, and Bendrix got out of bed to go see if they needed to head to the bomb shelter in the basement. Shortly after Bendrix left the room, a bomb destroyed part of his building. The blast shattered nearly all the windows except the stained glass window on his door, and it knocked Bendrix unconscious. Alarmed by the blast, Sarah went to find Bendrix and discovered his lifeless body trapped under a door. Frightened, Sarah ran back to Bendrix’s room where she uncharacteristically prayed to God, making a deal that if God would let Bendrix live, then she would end her affair and return to her husband. Just then, Bendrix walked back into his room with only minor injuries, and Sarah promptly went back to her house even though Bendrix begged her to stay. After Sarah left, Bendrix tried to call and write to her to no avail—Sarah had gone away with Henry to the country, and Bendrix didn’t see or hear from her again for two years.
Back in the present, Mr. Parkis has unearthed two important pieces of information: first, he’s discovered that the name of the man Sarah is visiting is Richard Smythe. More importantly, Mr. Parkis was able to steal Sarah’s diary, which he now gives to Bendrix. In the diary, Bendrix reads about Sarah’s promise to God and subsequent spiritual struggle; Sarah had always been indifferent about whether God existed, but after the supposed “miracle” of Bendrix coming back to life, she began to believe. Bendrix also learns that Mr. Smythe is an atheist who Sarah hoped could talk her out of believing in God so she could break the vow and return to Bendrix. Throughout the diary, Sarah wavers between her belief in God and desire to be with Bendrix. After reading this, Bendrix calls Sarah and tells her that he’s coming for her, even though she asks him not to. When Bendrix arrives, Sarah, who is seriously ill, runs out into the rain to escape him. Bendrix catches up with Sarah when she stops at a church and tells her about reading her diary. He tells Sarah to go back home and rest—as soon as she’s well, they can run away together. A few days later, however, Sarah passes away.
After Sarah’s death, Bendrix finds a letter she wrote him days before she passed away. In it, she tells him that she can’t run away with him because of her marriage and belief in God. This enrages Bendrix, who begins lashing out at God for preventing him and Sarah from being together. Henry, who has since forgiven Sarah for her affairs, asks Bendrix to help him plan the funeral. Father Crompton, a Catholic priest, reveals that Sarah had been interested in Catholicism, but Bendrix talks Henry out of giving Sarah a Catholic funeral. After Sarah’s funeral, Mrs. Bertram, Sarah’s mother, reveals that Sarah was secretly baptized as a toddler, further complicating the idea that Sarah was truly atheistic. Bendrix, a self-proclaimed atheist, begins grappling with a budding belief in God. Even though it is painful, Bendrix fully accepts that God is real because God had been strong enough to lure Sarah away from him. In the end, Bendrix prays to God to simply leave him alone forever, since love is too painful.
