The Boyfriend

As a teenager, Tom Brewer is a smart, isolated boy living with his abused mother, Luann, and his violent, alcoholic father, Bill Brewer. Tom falls intensely in love with Daisy Driscoll, the police chief’s daughter, and begins dating her, but his devotion is mixed with disturbing fantasies about injury, blood, and control. His closest friend, Slug, is equally unsettling and casually encourages violent thinking. Tom also once tutored Brandi Healey, a girl he kissed shortly before choosing Daisy. When Alison Danzinger, Daisy’s protective best friend, sees that kiss, she later uses it to pressure Tom to break up with Daisy and threatens to tell Chief Jim Driscoll that Tom was the boy Brandi had planned to meet the night she vanished.

At the same time, Bill’s abuse worsens. After Bill threatens Daisy in a sexually menacing way, Tom snaps, stabs him, and then deliberately cuts his throat rather than save him. Slug arrives and calmly helps Tom hide the body. Alison sees enough of the cover-up to become another danger in Tom’s life. Soon afterward Brandi’s body is found, and then Alison disappears and is later recovered tortured and mutilated. Tom initially fears Slug is responsible, especially after Slug talks about “problems” needing to be removed. But when Tom secretly meets Daisy at a late-night Dairy Queen rendezvous, he finds Slug dead and Daisy holding the gun. Daisy reveals that she, not Tom or Slug, killed Brandi out of jealousy, murdered Alison because Alison intended to expose Tom, and has now killed Slug as well. She forces Tom to back her story or die beside him. Tom agrees, realizing Daisy’s father will never believe she is the murderer. Afterward he tries to put distance between himself and Daisy, studies medicine, abandons surgery for pathology, and attempts a more ordinary life, but he never fully escapes either his own darkness or Daisy’s hold over him.

Years later, Sydney Shaw is thirty-four and still searching for a decent partner. Her Cynch date with Kevin is a disaster from the moment he arrives looking nothing like his photos. He insults her, pitches a pyramid scheme, makes her pay for dinner, then follows her outside and attacks her when she refuses to kiss him. A stranger intervenes, giving Sydney the chance to knee Kevin and escape. She is immediately drawn to her rescuer, though he leaves without giving his name. Shaken but fixated on the encounter, Sydney returns home to her building, where her friend Bonnie Griffin notices that Sydney is bleeding badly from a head wound. Sydney’s bleeding disorder, von Willebrand disease, deepens her embarrassment and vulnerability.

Sydney tells her friends Bonnie and Gretchen about the attack and decides to look for the mystery man. Before she can get far, violence hits closer to home. Kevin reappears and continues bothering her, and the next morning Sydney and Randy Muncy, the building super, discover Bonnie’s mutilated body in Bonnie’s apartment. Detective Jake Sousa, Sydney’s ex-boyfriend, takes the case. He learns Bonnie had been seeing a supposedly exclusive doctor who contacted her from a burner phone. Jake later reveals that Bonnie’s murder resembles an earlier killing of another Cynch user, with torture and a lock of hair taken from the victim, suggesting a serial predator targeting women through the app. Sydney grieves Bonnie, fears Kevin may be stalking her, and notices that Gretchen and Randy’s stories about the night of the murder are not entirely stable, though she hesitates to expose them.

Two months later Sydney forces herself back into dating and finally reconnects with the stranger who rescued her when a promising date named Travis faints at the sight of Sydney’s severe nosebleed. The rescuer helps, identifies himself as a physician, and asks her out. He introduces himself as Tom Brown, later corrected to Thomas Brewer, a pathologist and medical examiner. Sydney is quickly swept up by him. He is attentive, medically competent, and unfazed by her bleeding episodes. Yet warning signs pile up: he first gives the wrong surname, seems to contradict himself about where he works, has almost no online presence, reacts oddly when Sydney brings him to her real apartment building and mentions Bonnie’s murder, keeps a separate hidden phone for talking to her, hesitates to let her meet his mother, and shows a cold practicality when killing a trapped mouse in front of her. Tom also admits the only woman he ever truly loved died when he was sixteen, revealing how trapped he still is by his past.

Sydney’s suspicion sharpens when she finds Bonnie’s scrunchie beside Tom’s bed and discovers that the hidden phone contains only her messages. Convinced Tom may have killed Bonnie, she steals his water bottle and takes it to Jake for fingerprints. Jake confirms that Tom’s prints match unidentified prints from Bonnie’s apartment and another murdered woman’s home, but police cannot hold him because Tom has a solid hospital alibi for the night Bonnie died. Tom explains that he had dated both women, which accounts for the prints, and Jake reluctantly releases him. Sydney is not reassured. Meanwhile Kevin keeps finding ways to contact and frighten her, Randy plans to propose to Gretchen, and Tom reacts with visible shock when he sees Randy outside Sydney’s building. Tom urgently warns Sydney that she is in danger inside, but because Sydney has just decided she no longer trusts him, she dismisses the warning as more manipulation.

After breaking things off with Tom, Sydney goes upstairs with Gretchen and Randy. During an apparently warm evening, Randy proposes and Gretchen accepts. But when Sydney uses their bathroom, she opens the faulty toilet tank and finds a hidden freezer bag containing multiple locks of women’s hair tied with colored ribbons, including Bonnie’s. She concludes Randy is the serial killer. Before she can act, she returns to the living room dizzy from wine Gretchen has served. Tom starts pounding on the door, calling Gretchen “Daisy.” The truth breaks open: Gretchen is the same Daisy Driscoll from Tom’s past. She admits she put oleander in the wine, has been inserting herself into Tom’s life for years, joined Bonnie’s yoga circle, moved in with Randy as cover, and murdered women Tom cared about, including Bonnie and the earlier Cynch victims. She planted the hair in Randy’s toilet tank so he would take the blame.

Daisy then proves Randy was never her partner in the crimes by stabbing him to death while he is drugged and helpless. She plans to kill Sydney next and stage the scene so Randy appears to have murdered the women before Daisy killed him in self-defense. Tom arrives furious and terrified, explaining that Daisy had promised to leave him alone after her previous killings. Daisy counters that Tom is not innocent either: he has always been fascinated by blood, and Sydney’s bleeding disorder was part of what drew him to her. Tom does not deny his darker impulses, but he does try to save Sydney. He has already called the police before entering the apartment. When sirens approach, Daisy proposes that he run away with her. Tom gives in, unable to sever himself from her completely, but makes one demand: Sydney must live. Daisy agrees, and the two flee before police force their way in. Sydney survives the poisoning and Randy’s staged murder scene is exposed for what it was.

In the aftermath, Tom Brewer and Gretchen “Daisy” Driscoll remain missing despite a large manhunt. Jake becomes Sydney’s protector again, and the ordeal draws them back into a relationship. A month later Sydney seems ready to choose Jake and move forward. Then she finds an envelope in her mailbox containing a lock of dirty blond hair tied with a red ribbon and a note from Tom saying Kevin will not bother her anymore. The message implies Tom has killed Kevin despite promising Sydney that the deaths would stop. Sydney understands that Tom and Daisy are still out there and still capable of violence, but instead of turning the note over to police, she throws it away and goes upstairs to see Jake.