Published in 2025, Saltwater is a literary thriller by Katy Hays, author of the New York Times bestselling novel The Cloisters (2022). Like her debut, which is in development as a television series, Saltwater blends suspense with a richly detailed, atmospheric setting. The novel follows the wealthy Lingate family on their annual trip to Capri, an island that holds the dark secret of playwright Sarah Lingate’s mysterious death 30 years prior. Sarah’s husband, Richard Lingate, was accused of killing Sarah, but lack of evidence prevented any prosecution from going forward. This year, Sarah’s daughter, Helen, and her friend, Lorna, arrive with a secret plan: a blackmail scheme designed to win Helen her financial freedom by putting pressure on Richard and his brother, Marcus Lingate. But their plot to extort money from the family quickly spirals out of control, unearthing decades of deceit and culminating in another disappearance.

Set against the beautiful but treacherous backdrop of the Amalfi Coast, the novel explores Maintaining Wealth to Gain Impunity, showing how the Lingates’ glittering public image is a carefully constructed facade designed to uphold their power and invulnerability to the law. At the heart of the family’s dysfunction is Jealousy as a Corrosive Force, which fuels betrayals and murder. To escape this toxic environment, characters are forced into Survival by Adopting the Enemy’s Tactics, using manipulation, deception, and violence to secure their own freedom.

This guide refers to the 2025 Ballantine Books hardcover edition.

Content Warning: The source text and this guide feature depictions of graphic violence, substance use, addiction, physical and emotional abuse, sexual content, pregnancy termination, cursing, and death, including death by suicide.

Plot Summary

The wealthy Lingate family travels to the island of Capri, Italy, for their annual summer trip, marking the anniversary of Sarah Lingate’s mysterious death 30 years prior. The family includes Helen, Sarah’s daughter whose life is tightly controlled; Richard, Helen’s father and Sarah’s widower; Marcus, Helen’s powerful uncle; Naomi, Marcus’s volatile wife; and Freddy, Helen’s boyfriend. They are joined by Lorna Moreno, Marcus’s assistant and Helen’s close friend. Helen and Lorna have orchestrated a blackmail scheme. Using Sarah’s gold snake necklace, which they have mailed to the villa, they send an anonymous letter demanding €10 million. If the family doesn’t pay, the letter threatens to release damaging new information about Sarah’s death to the police. Helen’s motive is to gain financial independence after discovering Richard secretly liquidated a $2 million trust Sarah established for Helen. The family’s arrival is fraught with tension, not only from the blackmail threat but also from the presence of Stan Markowitz, a billionaire rival who was in love with Sarah.

The plan unravels as secrets held by both Helen and Lorna begin to surface. Lorna, who has a secret past as a party girl, during which time she slept with Freddy and worked for Stan, has a side deal to sell a dossier on the Lingates to Stan. Tensions between Lorna and Helen mount when Lorna nearly drowns Helen during a swim with a group of local men, including Ciro, Helen’s childhood friend and secret lover. The Lingates, desperate to avoid another scandal, agree to pay the blackmail. At a nightclub, Marcus gives Lorna a duffel bag filled with cash. Lorna is supposed to take a boat to Naples to make the drop, but Helen awakens the next morning to discover that Lorna has not returned. 

Helen worries that Lorna, like Sarah, is dead, which is seemingly confirmed by the calculated indifference from her family, who claim Lorna has simply stolen the money or been robbed. Helen and Stan later witness the carabinieri, the Italian police, recovering a woman’s body from the sea, which they believe is Lorna’s. The police visit the villa, confirm the body is Lorna’s, and reveal she was four to five weeks pregnant. They inform the family that the case of Sarah Lingate’s death has been officially reopened due to new evidence. The Lingates seize on the blackmail letter, presenting it to the police as proof of an external threat that led to Lorna’s death. The web of deceit unravels further when Freddy confesses to Helen that he slept with Lorna and may be the baby’s father. Helen, in turn, reveals her long-standing affair with Ciro, prompting Freddy to leave the villa. While searching Lorna’s room, Helen discovers a hidden manuscript of an unproduced play by her mother titled Saltwater.

The manuscript reveals several details about the Lingate family and Sarah’s life, including that the family is running out of money and that Sarah and Marcus were having an affair.. Despondent over the reopened investigation, Richard confesses to Helen that he killed her mother. He explains that the family has been secretly bankrupt for decades after his own father squandered their fortune, and he couldn’t afford the divorce Sarah demanded, as the public filings would have exposed their ruin. Likewise, the play would have exposed the truth of their family finances. He claims that during an argument, he accidentally pushed Sarah, heard her head crack, and, assuming she was dead, allowed Marcus to dispose of the body. Meanwhile, Naomi tells Helen that Marcus was having an affair with Lorna and gave her a check for $500,000, which Naomi believes was payment for an pregnancy termination. Naomi reveals, as well, that Marcus is her biological father, verifying the affair between Sarah and Marcus.

The family’s implosion culminates at a private ballet on the island of Gallo Lungo. Helen gives the Saltwater manuscript to Richard, who confronts Marcus with the play’s depiction of the affair. Marcus admits he is Helen’s biological father. Naomi reveals to Richard that Sarah was still alive after he pushed her, but Marcus chose to let her die to protect his secret. Consumed by 30 years of misplaced guilt and betrayal, Richard attacks Marcus. In the ensuing brawl, Marcus is knocked from a cliff and falls to his death. The police, tipped off by Stan and Ciro, arrive and arrest Richard. In the aftermath, a spiraling Naomi makes a final confession to Helen: She killed Sarah. After Marcus brought Sarah back to the villa, Naomi, in a jealous rage, pushed her from the cliff. She then admits she goaded Marcus into murdering Lorna to eliminate the threat of his second infidelity. Realizing the full scope of Naomi’s actions and that Naomi now plans to disinherit her, Helen poisons Naomi’s vodka with pills. Naomi’s death is ruled a death by suicide, and Helen inherits her entire fortune.

After Naomi’s death, Helen does not want to leave Italy. The villa’s caretaker, Renata, confesses to Helen that she is Sarah Lingate. The real Renata found Sarah, and in the darkness, Naomi mistook Renata for Sarah and pushed her from the cliff. Marcus identified the  body as Sarahs, and Sarah, fearing for her life, assumed Renata’s identity, raised Ciro as her own son, and watched Helen from afar for 30 years. Sarah sent the necklace to force a confrontation with Marcus. The Epilogue reveals that Lorna is also alive. The body found in the sea belonged to Martina, one of Stan’s party girls. On the night of her disappearance, Lorna, seeing an opportunity to take all the money and fake her own death, pushed Martina overboard and escaped with the cash. She now lives in Switzerland, though she encountered Helen once in Milan.