This Is Why We Lied, the 12th book in Karin Slaughter’s Will Trent series, was published in 2024. An instant New York Times bestseller, the novel follows Will Trent and Sara Linton’s honeymoon at the remote McAlpine Lodge, where a murder leads to revelations of generational trauma and abuse. As Will and Sara investigate the crime, Slaughter touches on themes relating to family, the effects of lies and secrecy, and the impact of the past.

This study guide uses the 2024 William Morrow Kindle edition.

Content Warning: The source text and this guide contain references to abuse, sexual assault, rape, incest, and substance and alcohol use disorders.

Plot Summary

Will Trent and Sara Linton, newly married, are on their honeymoon at the remote McAlpine Lodge in the Georgia mountains. Although they’re on vacation from their jobs as agent and medical examiner for the Georgia Bureau of Investigation (GBI), when they hear a woman scream late one night, Will and Sara quickly head out to find the source. Will runs down to the lake near their cottage and finds a cottage on fire and the lodge manager, Mercy McAlpine, stabbed and nearly dead. Before she dies, Mercy talks about her son, Jon, and forgiveness.

The novel then returns to earlier that day, 12 hours before the murder, and follows the hours leading up to Mercy’s death. Mercy’s parents, Cecil and Bitty, announce that they want to sell the lodge. A majority of the family members would have to vote to sell, but Mercy is adamantly against it. She threatens to reveal the secrets of Cecil, Bitty, her brother (Christopher), and her ex-husband (Dave) if they vote to sell.

Will, Sara, and the other guests check in and meet the McAlpine family. Will is shocked to discover that one of the men, Mercy’s ex-husband (Dave), was his nemesis at the children’s home he grew up in. After check-in, Mercy runs into Dave on one of the trails, and when she again refuses to sell, he strangles her until she nearly loses consciousness.

Later that night, the family and guests gather for cocktail hour. Like everyone else, Bitty pressures Mercy to sell, and when she refuses, Bitty fires her. Jon bursts into the room drunk and confronts Mercy about her refusal to sell. He says he wishes she was dead and runs out of the room. Will, Sara, and the other guests are shocked not just by the scene but by the way that Mercy’s family unanimously blames her for the scene.

That night, Sara wakes up, and Will isn’t in bed. He’s sitting on a bench outside their cottage, still bothered by that evening’s scene. She convinces him to go swimming at the nearby lake, but while there, they hear a woman scream. While Will runs toward another area of the lake, Sara runs toward the lodge. She sees Jon coming out of the lodge with a backpack and hears the woman scream twice more. While Jon goes back into the house, Sara runs to the lake, where she finds Will trying unsuccessfully to revive Mercy.

Will and Sara lack the authority to begin an investigation, so while she contacts their boss, Amanda, at the GBI, he gathers the family and guests and calls the sheriff. He’s surprised to note that when the family learns of Mercy’s death, they show no real grief. The sheriff, known locally as Biscuits, arrives, and Will quickly realizes that he isn’t interested in pursuing an investigation: As far as he’s concerned, Mercy and Dave had a fight that got out of hand. Jon and Dave have both disappeared, but no one seems concerned about that, either. Will and Sara find Dave at a nearby abandoned summer camp. Will is sure he’s the killer, and Sara cautions him to not let his biases interfere with the investigation. However, when Dave gets aggressive, Will injures the man and sends him to the hospital.

Meanwhile, Amanda and Will’s partner, Faith, arrives in the nearby town. Sara goes into town, with Mercy’s body, to perform the autopsy. Faith interviews Dave at the hospital and discovers that Mercy called Dave several times just before she died and left a panicked voicemail on the final call. In the message, she asked for his help, and Faith realizes that Mercy gave Dave an alibi.

After the autopsy and Dave’s interview, the team returns to the lodge, and Faith divides up the tasks of the investigation. Will sees Christopher’s friend Chuck heading down a trail and follows him. While they talk, Chuck looks increasingly ill, and when Will turns to leave, Chuck collapses and falls into the nearby river. Will brings him back to shore, but Chuck is dead. Sara and Faith arrive at the scene, and Sara informs them that Chuck has been poisoned, possibly by eyedrops put into his water bottle.

Sara tastes the liquor being sold at the lodge and realizes that it is too harsh for its luxury label. She and Will discover that Christopher and Chuck are making moonshine and bootlegging it at the lodge, and Mercy was laundering their money. Will searches the lodge’s equipment shed and finds the stills; however, he also finds empty eyedrop bottles. Christopher confesses to drugging Chuck as punishment for the way he acted around Mercy.

That night, everyone gathers again for cocktail hour, and Faith tells them about the bootlegging operation. Will purposely goads Dave into losing his temper, thinking he can get information from him, but instead he upsets Jon, who runs out of the room. Will tells Dave that Mercy’s final words were about forgiving Jon, and after a moment, Dave confesses to killing Mercy. Will, however, goes looking for Jon, realizing that Mercy’s words were meant to forgive Jon for killing her. He confronts Jon, who inadvertently reveals to Will that Bitty has been abusing him, and Mercy found out that night.

The story then returns to just before Mercy was killed. She visited Jon’s bedroom and found him and Bitty on the bed together. Although they were clothed, Bitty’s manner was abusive, and she clearly acted guilty when Mercy saw them. Mercy told Jon to pack a bag and went to her room to pack her own bag. She told Jon to meet her at the dining hall, but when he arrived, Bitty was with him, and Jon said that he wanted to stay.

Mercy grabbed Jon’s hand and pulled him down to the cottages near the lake. When they got to the shore, Mercy said that she was going to the police. However, Jon began to strangle her, and she cut him with a knife she’d put in her boot earlier. Jon grabbed the knife, and she ran into the nearest cottage, but he followed her in. As she ran out again, Jon stabbed her. As she dragged herself toward the lake, he repeatedly stabbed her, and then he set the cottage on fire and left. Minutes later, Will appeared by her side. She told him to forgive Jon and then died.