Anne is married to Walt for about ten years, until his death. Then, Anne is forced to move out of her apartment when it is marked for redevelopment. She downsizes her belongings to enter an assisted living facility and finds the boxes that Tobias had kept in storage after the sale of her Rolling Prairie house. The boxes contain various documents from Anne’s past, including her correspondence with Dr. Grassi, her family, and friends. Anne is struck by how little she can remember of her thoughts and worldview at a younger age, though the letters show how well she managed her relationships with each of her correspondents.

One of the last letters she wrote to Dr. Grassi is dated shortly before her departure for Japan. The letter describes Serk’s friendship with a Korean man named “Tom” (Tae-Min’s chosen American name). In her Thanksgiving letter of the same year, Anne shared that Serk had received a letter in Korean from Tom that greatly distressed him. It was a piece of propaganda, whose creators Tom feared. Sometime later, Tom’s wife reported that Tom had been kidnapped after getting a phone call. The phone was later found left hanging off the hook. Serk dismissed the matter as Tom abandoning his wife.

Anne suddenly remembers an argument she had with Serk, in which Serk urged Anne to dismiss her concerns about Tom and his wife. She also remembers that when Serk received the letter, Louisa was hoping to take off its stamps for her collection. Serk never gave her the stamps. Anne connects these two memories and wonders if Serk might have been afraid as well. She arranges for the boxes to be placed in storage.

While cleaning her old purse, Anne rediscovers the photo she’d kept of Serk and Louisa on the beach. When Louisa was still a teenager, Anne had argued with her about the photo since neither of them could remember who had captured it. Louisa wanted to keep the photo, so Anne hid it away in her purse’s inner pocket, forgetting it until the present moment. She calls Louisa, who finally remembers then that Serk’s female friend (Soonja) had taken the photo. Louisa knows the woman was unlikely to have been Serk’s mistress because of their dynamic. Louisa admits that she liked keeping the friend a secret from her mother, but the friend’s identity is still a secret to her too. She cannot remember what Serk and his friend talked about and claims that she couldn’t understand Japanese at the time. Anne sends a copy of the photo to Louisa.

Tobias comes across a protest calling for the resurfacing of a girl named Yumi. Yumi disappeared when she was walking home from tennis practice in 1977. She was 13 years old. The protest organizers connect her disappearance to over 30 other incidents of Japanese people living in coastal towns suddenly going missing. Tobias is so struck by the information that he collapses. When he revives, he offers to help.

The organizers include protest speaker Saho, and Yumi’s parents, Fumiko and Koji. At Saho’s apartment, they tell Tobias about their efforts. Yumi’s parents have always believed that she was abducted. They faced resistance from the police, who urged them to accept the official conclusion of death. Saho’s brother Takashi and his girlfriend disappeared in 1979. Saho led the police to the beach where Takashi was planning to propose to his girlfriend, but all they found was his car in normal condition. The police concluded that the couple died at sea, but Saho refused to believe this. She became certain that they were also abducted.

Saho’s parents became extremely protective of her after Takashi’s disappearance. They died when she was in university, which caused her to experience suicidal ideation. That was when she met Fumiko and Koji, who visited her university to bring awareness to Yumi’s disappearance.

Saho’s abduction theory was bolstered in the early 1990s when a North Korean defector who had previously worked in espionage revealed that he had been taught how to blend into Japanese society by a prisoner who had been abducted from Japan. The abductions were part of a larger program to install government agents across the archipelago. Since then, Saho and Yumi’s parents have connected with many other families who claimed that their loved ones had also been abducted. This way, they established the patterns that defined North Korea’s abductions.

It becomes clear to Tobias that all these families rely on each other to sustain hope. Over the next few months, he participates in awareness-raising campaigns. He refrains, however, from engaging in any public-facing activities out of fear that his whiteness will distract from advocacy. This drives tension between him and Saho, who insists that attention is what they need. Tobias eventually relents when Yumi’s parents hold an event to mark the next anniversary of the disappearance.

At the event, Tobias understands that Saho wanted him to draw attention because the public has already lost interest in Yumi’s case. A woman comes up to Tobias and apologizes for her initial resentment of Yumi’s parents. Tobias tries to convince the woman to speak with them, but she is so reluctant that she starts to weep. Tobias gets up to console her, but faints. Saho later explains that the woman mustered the courage to speak to Yumi’s parents, sharing that her own brother disappeared. When he learns this, Tobias realizes that the woman’s brother is Serk.

Two years into their marriage, Louisa and her second husband, George, go to Hawaii. Just before they arrive, Louisa realizes that she has already been to Hawaii, even though she told George that she hadn’t. She recognizes its smell, a sensation that only grows stronger.

Louisa has a wonderful honeymoon. When they arrive in Kauai, their last stop, Louisa once again remembers coming to the island. She calls Anne, who reveals that Hawaii was a stopover during their transit to Japan. Louisa cannot believe that she has forgotten all about this trip. Her bewilderment irritates Anne.

When they return from the honeymoon, Louisa remembers that she still has her college duffel bag, which holds all of her belongings from the summer trip to Paris. In it is the diary entry that Tobias had returned to her. She realizes that the entry is not describing her father’s death in Japan, but their trip to Hawaii. Louisa calls Anne because she now remembers sharing a memory with Dr. Brickner of Serk going down into loud water. Anne doesn’t think this makes any sense because Serk was afraid of swimming.

Tobias emails Louisa that he is in New York and will visit her shortly. Louisa assumes that he has come to discuss Anne’s mounting health issues, but Tobias is actually there to talk about Serk, who he believes is still alive. He appeals to Louisa to listen to his theory, though he is clearly paranoid about his surroundings. During his explanation, he shows her a picture of an Asian woman, sparking recognition within Louisa.