Written by Ruth Ware in 2024, One Perfect Couple is a suspense thriller that follows a virology researcher named Lyla Santiago as she reluctantly agrees to become a contestant in a reality television show alongside her boyfriend, Nico. As the two join the other contestants on a remote Indonesian island, Lyla must confront a deadly combination of natural disasters and human treachery as she struggles to survive.

Ruth Ware is a pseudonym chosen by author Ruth Warburton to separate her crime thrillers from the young adult novels that she previously published. Known for penning suspense thrillers, Ware has published multiple best-selling novels, and her books have been translated into over 40 languages and distributed worldwide. Several of her titles, such as In a Dark, Dark Wood (2015), The Lying Game (2017), and Zero Days (2023), have been optioned for film and television.

This guide refers to the Kindle e-book edition.

Content Warning: The source text and this guide discuss intimate partner violence, physical and emotional abuse, violent death, murder, suicide, and anti-gay bias.

Plot Summary

A 32-year-old postdoctoral researcher named Lyla Santiago is listening to her boyfriend, Nico, discuss his new hopes to become a reality television star in a show called One Perfect Couple. Because the show is romantically themed, Nico needs Lyla to apply along with him. Although Lyla is cynical about Nico’s acting ambitions and dismissive of reality television in general, she reluctantly agrees to the interview process. In her own work, her lab results are increasingly discouraging, and she is beginning to think of abandoning her research career. Lyla’s doubts about the show intensify when the producer clearly sexualizes her and she learns that the premise requires couples to change partners when one of them is eliminated. Lyla resolves to be eliminated early so that she can return to her job.

Upon arriving on the Indonesian island that will serve as the set of the show, Lyla meets some of the other contestants, including a shy fellow academic named Joel Richards whose partner, Romi, is a makeup and style influencer. She also meets Conor Brian, a charismatic YouTuber, and Dan, who reveals that he is gay and is only participating in the show to boost his career and to provide his best friend, Santana, with a change of scenery. Basil “Baz” Farrier, the producer, is irascible and demanding and upsets everyone with his ban on electronics. He also displays a particular tension with Conor.

Although Lyla is somewhat mollified by the idyllic setting, she is intimidated by the glamor of the other contestants. The show’s first task brings her to an existential crisis; as she answers questions about her ideal future and romantic life, she realizes that Nico does not share her dreams. As time goes on, Lyla gets to know a glamorous woman named Angel, whose partner, Bayer, runs a gym, and she also befriends Conor’s shy girlfriend, Zana, who confides her terrible fear of water.

Nico fails the first task by failing to demonstrate a basic knowledge of Lyla’s preferences. When he is eliminated, he is furious and accuses Lyla of betraying him. The tension only builds when Joel and Lyla are sent to an offshore villa overnight because the results of their questionnaires reveal that they are more compatible. In these early chapters, the primary narrative is interspersed with interludes set some days in the future, in which Lyla and the other contestants are radioing for help after an unspecified disaster.

The narrative returns to the primary storyline. That night, a severe storm damages the entire island, forcing Joel and Lyla to swim to the shore. Santana is severely injured, and Romi and a producer are killed by falling trees. Assuming that the production yacht has been lost in the storm, Conor helps the survivors gather supplies and prepare for a long stay. Bayer becomes increasingly belligerent and rejects Conor’s plan for rationing food and water. Santana, who has Type 1 diabetes, is in particular danger given the absence of refrigeration for her insulin. When Bayer discovers that Conor has moved all the food and water to an offshore villa, the two fight, and Bayer is killed. Conor is unrepentant, increasing Lyla’s anxiety about their situation. Santana reveals that a friend of hers dated Conor when he was in his twenties and she was only 17 and that she later died by suicide.

Dan tries to confront Conor, who coolly reminds him that as the stronger figure, he can win any argument. He stresses that morality or democracy do not apply. Joel sides with Conor, insisting that the group needs a strong leader. He ignores the group’s concern for Zana and dismisses Dan’s evidence that Conor’s YouTube channel is misogynistic and reactionary. Meanwhile, Lyla and the other women discover that Conor is abusing Zana. Tensions reach another crisis when Santana’s insulin goes missing, and Dan disappears soon after resolving to confront Conor about their situation. Conor later claims to have found Dan’s body, but when Lyla finds a bottle of Santana’s insulin in Dan’s hand, she realizes that Dan did confront Conor, who likely killed him. Angel reminds Lyla that only Joel could have easily stolen the insulin. The situation grows more desperate when the radio’s battery dies. Throughout the latter half of the novel, the interludes feature deliberately fictionalized diary entries in which Conor is depicted as kind and gentle and the deaths are explained as the results of bad luck.

As the story continues to unfold in the narrative present, Conor begins controlling the women’s access to water, requiring them to climb coconut trees in exchange for their rations. During this effort, Zana sees a boat, and the others build a bonfire. When Conor fails to join their efforts to secure rescue, Lyla realizes that Conor hopes that she and her friends will die before they can be rescued, as this would allow him to escape accountability for his crimes. Angel and Santana convince Lyla that the only way to survive is to kill Conor by drugging him and Zana with sleeping pills and then poisoning him with Santana’s remaining insulin. However, their plot soon goes awry, as Angel accidentally drinks the drugged coconut water meant for Zana. Conor awakens as soon as Santana injects him with the insulin, and Lyla is injured in her attempt to escape. Zana saves Lyla’s life when she hits Conor with a large bottle of water and jumps into the ocean to drown him. Lyla swims out to save Zana from the current but feels herself begin to drown on the way back.

Lyla awakens on shore to find that Santana is recuperating with Angel and Zana’s help. Angel finds Joel dead, either by suicide or as another victim of Conor’s cruelty. The women work together to revive the radio battery, and Angel manages to contact a ship. However, Zana is not comforted by the prospect of rescue, noting that she might still face arrest for her role in Conor’s death. Lyla and the others decide that to truly save themselves, Zana will write a false diary in which Conor is portrayed as a beloved hero and all the deaths are nonviolent.

After their rescue and recovery, the women compare notes on their pasts. Lyla realizes that all the contestants either have some history with Conor, as Santana does, or have a known history as feminists who are critical of domestic abuse, like Lyla and Angel. Upon learning that Conor once had a romantic relationship with Baz’s underage niece—a relationship that led the girl to die by suicide—Lyla deduces that Baz planned to use the reality show to expose Conor’s role in his niece’s death. Zana is embittered by the knowledge that she has instead glorified Conor’s memory, but the others tell her not to regret their survival. Nico, Baz, and the other production staff are presumed lost at sea.

Lyla returns home and puts her old sim card in a new phone, catching up on weeks of missed messages from anxious friends and colleagues. She is stunned to discover a last text from Nico, sent before his death. He apologizes for his anger and professes his love. He warns her about Conor’s history with Baz, validating her hypothesis about the secret motive behind the show.