Don't Let Him In

Don’t Let Him In is a 2025 psychological thriller by British author Lisa Jewell. Jewell specializes in the domestic suspense genre, and her nearly two dozen novels often focus on the intricacies of human relationships. These include bestsellers like I Found You, The Family Upstairs, and Then She Was Gone. Don’t Let Him In follows widow Nina Swann’s developing relationship with the charming and polished Nick Radcliffe, whom Nina’s daughter, Ash, doesn’t trust. When Martha, a woman in a nearby town, becomes worried about her husband Alistair’s frequent absences, the three women confront a shocking truth. Through their experiences, the novel explores themes including The Insidious Nature of Psychological Manipulation, The Importance of Women Helping Other Women, and The Universality of Vulnerability to Scams.

This guide is based on the 2025 Atria Books hardcover first edition.

Content Warning: The source material and this guide feature depictions of death, graphic violence, mental illness, cursing, sexual violence, and death by suicide.

Plot Summary

Following Paddy Swann’s funeral, a man arrives at the Swann home in Whitstable to deliver condolence flowers. Nina Swann and her children, Ash and Arlo (both in their twenties), are grieving Paddy, who was murdered by a man named Joe Kritner. Unbeknownst to the Swanns, the delivery driver is Nick Radcliffe, a man who once knew Paddy and intends to make the Swann family suffer.

Two months later, Nick sends the Swanns a condolence card, explaining that he knew Paddy from their early days working in a London restaurant. Nina is touched by the card’s sentiments.

Four years earlier, Nick—going by the name Jonathan Truscott—describes life with his former wife, Tara. He is proud of his ability to read her emotions and manipulate her, and he has been so successful that she is still convinced that he is a loving husband despite the fact that he has embezzled nearly all her money.

Now, four months after Paddy’s death, Nick sends Nina a Zippo lighter that he says once belonged to Paddy. Ash keeps the pink box it arrives in to put trinkets in. Nina and Nick begin an email correspondence; after a few months, their connection becomes romantic.

Meanwhile, Martha Grey, a florist in a nearby town, is disappointed yet again by her husband Alistair’s unpredictable work schedule. Alistair—aka Nick Radcliffe—is often away for work several days at a time. Now, he cancels the first weekend away they have scheduled since the birth of their daughter, Nala, who is now a toddler.

The narrative again flashes back to Nick’s marriage to Tara four years earlier. He disappoints her by claiming that he has to work during a gathering they planned to host. He texts Martha (who is, at this time, his new girlfriend) to let her know that he can spend the weekend with her. When Nick comes home after his weekend with Martha, the police are waiting to question him about harassing women on the street. He can see that Tara’s trust in him is seriously damaged.

In the present, Ash learns that her boss, Marcelline, has a pink box identical to the one Nick sent Paddy’s lighter in. Marcelline says that she bought some soaps in the box but does not remember where. Later that day, Ash finds a man’s gold wedding ring on the floor by her mother’s bed. Nina says that it must be a memento from Nick’s engagement to Ruth, his deceased fiancée.

The narrative flashes back to four years earlier again. After an extended visit to Martha, Nick returns home, and Tara tells him to leave. He convinces her to think it over for a week and agrees to stay elsewhere while she makes up her mind.

Now, Martha accidentally discovers her husband Alistair’s burner phone, stashed in a doctor’s bag that he told her he inherited from his father. He explains and manages to placate her, but a few days later, he disappears overnight again. While he’s gone with their only car, Nala becomes sick, and Martha has to call a friend to take them to the hospital.

Ash meets with Jane Trevally, the woman Paddy was involved with before he met Nina. She tells Jane about Nick and the lighter, but Jane tells Ash that Paddy never carried one. Jane agrees to help investigate Nick.

Four years in the past, Nick arrives at the home of Amanda, to whom he was married decades before as “Damian.” He plunged her deeply into debt and then faked his own death. Now, he claims that he had to disappear because of threats to him and his family. He asks whether he can stay with her, and she agrees.

Now, when Nick can’t persuade Nina to invest in a new restaurant venture in Bangate, he shows the same property to Martha and convinces her to start a flower shop there. She is reluctant to take out the large loan, but he persuades her that he intends to leave his job and devote himself full-time to her, Nala, and the florist business.

Four years earlier, Nick sneaks into Tara’s house and runs into her adult daughter, Emma. Nick blames Emma for the fact that Tara won’t sell her house to fund an investment he wants to make in a Mayfair wine bar. When he meets with Luke, his potential partner, Luke tells him that he has decided to go with a different partner, who has ready funds. Nick goes to Amanda’s and persuades her to ask their sons for money, claiming that he needs to travel for a heart condition treatment. In reality, he wants the money to take Martha on a fancy date.

Now, Jane shows Ash an online profile with Nick’s photo but another man’s name: “Justin Warshaw.” He is advertising as a life coach. Jane also says that the people at the Mayfair wine bar have never heard of Nick. The next day, they call a woman named Sarah, one of “Justin’s” former coaching clients. Sarah tells them about going deeply into debt to pay for the services Justin pressured her into. She also reveals that he was married to a woman named Laura, and they had two young daughters. She gives them information that leads Ash to the house they lived in.

When Ash tells her mother, Nina makes excuses for Nick, but she agrees to ask Nick about the “Justin” photo and try to get him to take her to the Mayfair wine bar. Two days before Christmas, Nick unexpectedly shows up to give Nina, Ash, and Arlo Christmas presents, and Ash brings up his past in life coaching. He readily admits to it, seeming unconcerned.

When Nick arrives home at Martha’s that night, he tells her that his mother had an emergency. He says that she has developed dementia, and he will need to travel to her house often. He will also need money for her care.

Four years earlier, Nick convinces Amanda to borrow a large amount of money for medical treatments he claims to need. He uses the money to take Martha on vacation and proposes that they move in together. When Nick gets back to Amanda’s, Tara unexpectedly arrives and tells Amanda that the man she knows as “Damian” is the same man Tara knows as “Jonathan.” She tries to show Amanda a photo of Nick and Martha together. Nick strangles Tara and convinces Amanda that Tara has been threatening him for years. He says they must hide the body and cannot risk going to the police.

In the narrative present, Nick gives Ash a pink box of fancy soaps for Christmas; the box is identical to the one the lighter came in. He claims he sold his shares in the wine bar and made an offer on the Bangate property, still hoping to go into business with Nina. Ash is heartened by her mother’s confusion and suspicion.

On Boxing Day, Martha searches Alistair’s things and finds a Paddy’s Restaurant receipt from the night that Nala was ill. Furious, she finally accepts that he is having an affair. When he returns home, claiming that he will need to be away again soon to help his mother, she accepts his lie calmly. After he leaves, she goes over her business accounts and discovers that he has been embezzling.

A year after killing Tara, Nick is living happily with Martha. One night, he takes Martha out to dinner at Paddy’s Whitstable restaurant. They meet Paddy himself, and Nick is furious when he realizes that Paddy is a man he once worked with at a Mayfair restaurant, who was condescending to him. Nick begins learning everything he can about Paddy. He stalks Paddy’s daughter Ash in London and learns about her crush on her married boss, Ritchie Lloyd. He travels to the coast to spy on Nina and learns that both Paddy and Nina are having affairs.

Ash tracks down Laura, who explains how her husband, “Justin,” manipulated her and then disappeared, leaving her with huge debt. Laura also says that Emma, Tara’s daughter, contacted her four years previously, looking for information about “Justin.” Ash is chilled to learn that Tara disappeared and that “Jonathan” has a history of stalking and harassment.

Ash discovers that the pink soap box comes from a gift shop in Enderford. The next day, she finds the shop, Martha’s Garden. She learns from a shop assistant that Nick is currently married to its owner, using the name “Alistair.”

Meanwhile, Martha investigates Alistair’s movements—she visits the places his car was parked when she briefly hid a tracking device in it. One of these places is Nina Swann’s house, and Martha realizes Alistair must be having an affair with her. She goes to the Swann house and rings the bell, but no one answers. A short time later, Nick leaves Nina’s and finds a temporary place to stay with an elderly woman, Jesse, for whom he has been an escort.

Three months before the narrative present, Nick and Nina have their first date. Nina explains what happened to Ash in London: Convinced that Ritchie Lloyd had been writing her love letters, Ash showed up at his family vacation in Ibiza. He filed stalking charges, and Ash briefly stayed in a mental health facility before moving back in with her parents. Nina also shares about her difficult marriage to Paddy.

Ash meets with Emma, who asserts that the woman Nick lived with in Tooting when Tara disappeared is key to solving Tara’s murder. When Ash gets home, Nina is concerned because she cannot find Nick. Ash suggests she check their Ring footage. They see both Martha’s visit and Nick’s departure. Ash decides that it is time to tell her mother everything. This time, Nina believes her and apologizes for not trusting Nina earlier.

Ash and Nina visit Martha, who is shocked by their story but agrees to cooperate with them to expose Nick. She sends “Alistair” a text, pretending to be worried about him and ashamed that she suspected him of having an affair. He agrees to come back home. Ash and Jane visit the Mayfair wine bar and learn that Nick harassed the owners for months until Luke died by suicide. Ash visits Joe Kritner, her father’s killer, in prison and learns that Nick manipulated him into killing Paddy.

Ash and Jane track down Amanda’s address, but her son, Sam, tells them that she disappeared four years ago. They explain what happened between Amanda and Nick but do not share their belief that Nick likely killed her.

Nick returns to Martha’s with £20,000 he stole from Jesse. She greets him enthusiastically and asks him to take another look at the Bangate property with her. At Bangate, a crowd of Nick’s victims and three of his children wait to confront him. When it becomes clear that he is going to be prosecuted for his crimes, Nick escapes into the sea, appearing to drown.

Ash and Nina move forward with their lives. Nina decides to sell her house and acquire a business partner, and Ash is ready to re-establish her independent adult life. A letter arrives from Nick—sent shortly before the confrontation on the beach—prompting Ash to have an honest conversation with Nina. She compares the letter to her letters from Ritchie and realizes that they were actually written by Nick.

Nick arrives in the Algarve after faking his death. Amanda is waiting there in the cottage where she has lived for the past four years. She is still in love with Nick, but now that she is fully aware of his manipulations, she is no longer willing to cover for him. As Nick walks toward her along the beach, she moves aside to allow the police to step out and arrest Nick.