The Missing Half

The Missing Half (2025) is a psychological thriller novel by Ashley Flowers. The narrative follows Nic Monroe, who lost her sister Kasey seven years earlier in an apparent kidnapping and still struggles with guilt over never discovering what happened to her sister. However, when she is approached one day by Jenna Connor—who also lost her sister seven years before—the two form a friendship in their quest to finally uncover the truth. As they start to revisit the past, they discover lies, secrets, and dangers hidden in their small Indiana town. Through their journey, the novel explores themes of The Strength of Family Loyalty, The Impact of Media and Public Perception, and The Lasting Effects of Trauma and Grief.

This guide uses the 2025 first hardcover edition of the novel, published by Bantam Books.

Content Warning: The source material and guide feature depictions of sexual violence, rape, graphic violence, alcohol use and addiction, cursing, and death.

Plot Summary

Nic Monroe struggles with the disappearance of her older sister Kasey seven years before the start of the novel. Nic works a dead-end job at Funland, a children’s birthday destination, a job she only has held for the last several years because the manager, Brad, is her parents’ best friend. Nic recently got a DWI and has dealt with alcohol use disorder for years.

One day after work, Nic is stopped by a woman who introduces herself as Jenna Connor. Jenna’s sister Jules disappeared two weeks before Kasey. Although the two cases were connected by the media, the police never found anything linking the two. Jenna says that she found her sister’s diary, which convinces Nic to talk with her to see if they can find a connection between Kasey and Jules.

Nic tells Jenna about the day Kasey disappeared. That morning, Nic woke up and the house was empty, as Kasey never came home the night before. She spent the day calling and texting her sister but only realized something was wrong when she went to the record store where her sister worked, and Kasey’s coworker Lauren told her that Kasey never came to work. When Nic got home, the police were there: Kasey’s car was found abandoned by the side of the road, the driver’s side door open and all her belongings inside—just as Jules’s car had been found two weeks before.

After Jenna and Nic go through their sisters’ histories, trying to find a connection between them, Jenna admits that she lied about the diary. Enraged, Nic kicks her out of her apartment, but a few days later, she decides to visit the barbecue place where Jules worked for a few years before her disappearance. She discovers that the restaurant is next door to the record store where Kasey worked.

Despite her annoyance, Nic decides to tell Jenna what she discovered. They reach out to Lauren, who tells them that she stopped working with Kasey that summer, moving next door to work at the restaurant. She also tells them that the restaurant’s manager, Steve McLean, sexually harassed the women employees.

Nic and Jenna find out that McLean has been arrested several times for different sexual assault-related crimes. They speak with Detective Wyler, the detective from Kasey’s original case, who tells them that they ruled out McLean as a suspect at the time of Kasey’s disappearance. Despite this, Nic and Jenna decide to go to the restaurant.

When they discover that McLean is still working there, they watch him throughout work and then follow him to a nearby pub. He invites them to sit with him and admits to knowing Jules and Kasey. To Nic’s surprise, he tells them that Lauren hated Kasey. Throughout the conversation, McLean makes them uncomfortable by deliberately goading Nic with comments about Kasey. Finally, Nic becomes enraged, spitting in his face.

Nic and Jenna decide to revisit Lauren, who will only speak to them through her closed door, insisting that she is in danger. Jenna realizes that someone must have scared her into silence. She suggests that Nic’s manager Brad may be responsible—he knew they were talking to Lauren. They tell Lauren that they know about Brad’s involvement; she immediately invites them in, asking how they learned about Brad and Kasey’s affair.

Lauren tells them that Brad and Kasey slept together that entire summer. She tried to get Kasey to end it, but she refused. The news shocks Nic—both the relationship and the fact that Kasey never told her about it. Lauren then reveals that someone threatened her by asking her four-year-old daughter to pass on a message, and she refuses to talk about Kasey or the case anymore.

Nic searches Kasey’s car and finds random receipts and papers, her collection of CDs, and a business card from an auto body shop. She shows Jenna, who notes a song lyric written on a CD—which matches Kasey’s bumper sticker—as well as the gas mileage on the vehicle. Kasey had driven over 500 miles since her oil change only a couple of weeks earlier. The business card also doesn’t match the shop that did the oil change. In the end, they decide to ask Nic’s dad about Brad.

On Saturday, Nic visits her dad, with plans for Jenna to meet her there. They have an awkward dinner, and her dad refuses to talk about Kasey’s case. In the end, however, she learns that Brad did not go on their father’s annual fishing trip or to his family reunion, which took place the weekends of both disappearances, destroying his alibi for both.

When Jenna doesn’t show up at her father’s house, Nic becomes concerned. She goes to Jenna’s house, where Jenna says that she has to stop investigating because her mother is ill and needs her attention. Although Nic can tell she is not being completely honest, Jenna insists that she needs a break.

Nic decides to confront Brad, but when she talks to him, his wife Sandy joins them. Sandy admits to knowing about the affair, which is new information to Brad. She says that she demanded Kasey end the affair, and Kasey asked for money in exchange. Just before Kasey’s disappearance, Sandy gave her $7,000, but she insists that they had nothing to do with Kasey’s disappearance.

On her way home from Brad’s house, Nic is pulled over by the police. Upon discovering that she drove without a license—having lost it due to a DWI—and has an arrest warrant out for missing a trial date, they arrest her. After spending a night in jail, she spends several days at home, drinking. When she wakes up one morning to an email from Detective Aimes, the officer who took over Kasey’s case, she decides to stop drinking and solve the case.

Aimes tells Nic that they have a piece of evidence they never released to the public: One of Jenna’s hairs was found in Kasey’s car. They believe the perpetrator inadvertently transferred it there. She also reveals that she met with Jenna the week before and told her all the same information.

Nic goes to Jenna’s house and breaks in while she is at work. She checks Jenna’s computer and learns that Jenna spoke with one of Jules’s old friends, who told her that Jules was raped by McLean. She then finds a gun and realizes that Jenna plans to confront McLean. However, at that moment, Jenna comes home from work.

Nic sneaks out of the house and hides in Jenna’s truck. Jenna packs the truck, including the gun, and Nic decides to stay in the truck. After several hours, Jenna arrives at a house in the middle of nowhere. She gets out holding the gun, and Nic follows her in the shadows with a hammer.

A woman answers the door, and Nic realizes with shock that it is Kasey. Jenna confronts Kasey about killing Jules. She explains that she recognized the song lyric on the CD, which reminded her of the night Jules died: She saw the bumper sticker with the same lyric leaving the scene. Further, the auto body shop records prove that Kasey’s car was damaged. She deduces that Kasey hit Jules with her car and then faked her own abduction to disappear.

Realizing she has to make a choice, Nic considers everything that Jenna has done for her. However, she decides that Kasey is her sister, which means more than anything else. She hits Jenna over the head with the hammer, killing her.

As Nic struggles with what she has done, Kasey jumps into action. They wrap the body in a tarp and put it in the back of the truck, then clean up the blood. Through it all, Nic questions Kasey about the night Jules died, as something seems wrong to her. Kasey finally admits that she lied: She isn’t the one who killed Jules. Nic, who was driving drunk, killed her, and Kasey only covered it up.

The narrative then flashes back to seven years before. Nic calls Kasey in the middle of the night, saying that she is drunk and hit a tree. When Kasey gets to the scene, she puts Nic in the car. Nic immediately falls asleep, but Kasey finds Jules’s body and her car. She puts Jules in her trunk, stages the car to look like an abduction, and dumps the body in a swamp. A few weeks later, the police ask questions at the restaurant and record store, and Kasey decides to stage her own disappearance and moves to Nashville.

In the present, Nic is overcome with guilt over Jules’s death and Kasey’s actions. Kasey tells her to get over it, as they have to hide the body. She drives to the same swamp where she left Jules, and they drop Jenna into the water. As they do, Nic notes that both sets of sisters have been reunited, although she isn’t sure the “right” pair survived.