The Lake

The Lake is a young adult psychological thriller written by Natasha Preston and published in 2021. Preston has authored dozens of young adult novels in the thriller/psychological horror genre, many of which are New York Times bestsellers, including The Lake. Preston was a London Evening Standard Young Rising Star. The Lake takes place at a typical summer camp that experiences a dark twist. Esme and her best friend Kayla return to camp to find someone from their past stalking them, and they quickly discover The Weight of Secrets, Guilt, and Lies. Kayla and Esme’s friendship is tested as they experience The Effects of Fear on Human Bonds, and Esme goes through intense periods of self-doubt, demonstrating The Thin Line between Reality and Imagination. Preston situates these themes within an accessible young adult framework, using the camp’s familiar routines—lake swimming, cabins, games—as a backdrop for examining how guilt and trauma reshape ordinary spaces. The book combines suspense with psychological study, illustrating how unresolved past events can shape identity and relationships in the present.

This guide uses the 2021 Penguin Random House paperback edition of the novel.

Content Warning: The source material and guide feature depictions of bullying, animal death, graphic violence, physical abuse, emotional abuse, and death.

Plot Summary

Esme arrives at Camp Pine Lake for the first time in years, returning as a counselor-in-training with her best friend Kayla. The camp is full of energy and children ready to have fun, but Esme and Kayla remember a night 10 years ago, when they attended the camp. They accidentally started a fire in the woods and met a runaway named Lillian. Lillian tried to show the girls a deer head she had cut off, terrifying them. Kayla pushed Lillian, and she landed in the fire, causing severe burns. Esme and Kayla ran, unsure if Lillian got out safely. They’ve kept the incident a secret.

Being at Camp Pine Lake revives Esme’s guilt. When she mentions the fire, Kayla insists it wasn’t their fault and that Lillian probably got away safely, but Esme can’t shake the feeling that someone is angry with her. Soon after, a note falls out of Kayla’s pocket, telling them they have been “bad,” and someone paints a warning on the back of their cabin. People see strange figures in the woods, and Esme thinks she catches a glimpse of Lillian when the counselors-in-training sneak off to town. On the way back, they are chased and photographed.

Cigarette butts are found on the grounds, and someone leaves a knife in the cabin door with a warning not to call the police. As Esme’s paranoia grows, Kayla urges her to let it go, but Esme is convinced Lillian is trying to scare them into confessing, especially when she finds Lillian’s initials carved into the wall. While other staff shrug it off as a prank, Esme knows it’s deliberate and ill-intentioned. Later, an inflatable in the lake is punctured, causing risk to the children’s safety, and a threatening sign is axed to the cabin. As fear spreads through the camp, Esme suspects Rebekah, another counselor-in-training, might be helping Lillian, especially after overhearing a strange phone call and noticing her constant questions. Haunting noises are heard through the woods, and rumors spread about a stalker on the grounds. Kayla’s anxiety worsens, and Esme struggles to continue trusting Kayla as she flips back and forth on what is going on. Andy calls a staff meeting, determined to keep the camp’s reputation intact by dismissing the threats as pranks and refusing to involve the police.

Esme considers fleeing the camp but worries about Kayla’s fragile mental state and her own family’s judgment if the secret comes out. When a group, including Esme, ventures into the misty forest to find the culprit, flashing lights blind them, and Esme becomes temporarily lost. Alone and disoriented, she sees Lillian in the trees but doesn’t confront her. Instead, she waits for safety and runs back to camp. Later, Esme confides in Kayla her suspicion that Rebekah might be connected to Lillian. Together, they devise a plan to search Rebekah’s cabin, discovering a diary with a drawing of fire. When Rebekah comes back, Esme hides and overhears Rebekah talking to her mom. She gets out without being noticed. Afterward, Olly invites Esme on a date, and while she likes him, she suspects he is somehow involved in what’s going on.

One evening, Olly tries to get closer to Esme, but her fear and paranoia make her pull back. Eventually, Esme opens up about the secret she has carried for years. Olly reveals he was present the night it happened and shares his own regret for not helping Lillian, though Esme suspects Olly still has secrets. Late one night, Olly and Esme find a dead deer carcass in the food hall. The camp loses power, and Esme and Olly spot Lillian and another person outside, but they disappear moments later. Andy suspects the culprit is a girl, and Olly suggests looking through camp files to identify “LC.” Esme finds Rebekah’s file and learns she lives in town, but no record of Lillian exists.

The next day, Esme shares her findings with Kayla and convinces her they must sneak into town to find Rebekah’s house and learn more about Lillian. Kayla is hesitant but agrees. Esme ventures out at night and meets Rebekah’s nana, who reveals that Rebekah lied about where she would be this summer. When Esme gets back to camp, she finds a warning note indicating that Lillian is watching closely. Later, Esme wakes in the forest, disoriented and unsure how she got there. She follows footprints until she comes across a deer carcass, disemboweled and hanging from a tree. Esme runs back to camp to find Kayla. Kayla comforts Esme, and together they decide to take control of the situation. That night, they sneak out to confront Lillian but find her armed with a gun and ready for revenge. Esme confronts Lillian, asking why she couldn’t just talk, but Lillian wants to get even.

Lillian reveals her deep pain as a result of her injuries, neglect, and the financial hardship her family faced. She leads Esme and Kayla to a cabin where she questions them and demands answers. The situation becomes tense and dangerous as Esme tries to reason with her, but Lillian insists on revenge, revealing that she has already killed Jake. Kayla pleads for the horror to end, but Lillian insists that Kayla can either kill Esme or be killed herself. Faced with this, Kayla makes the decision to protect herself. Esme pushes Kayla into Lillian and uses the moment to escape back to camp, where she finds the police have arrived. Rebekah admits to having helped Lillian initially but is now afraid of how far things have gone. When Lillian reappears, she shoots and kills Olly, Rebekah, and Kayla. Esme tries to help, but eventually has to run. Lillian leaves Esme with the gun, and Esme is then found by the police.