Kevin grabs Sydney's wrists after she refuses to kiss him; a passing stranger shouts a warning and Kevin flees.

Neighbor Bonnie tells Sydney she believes the attractive doctor she has been dating will soon commit to a relationship.

Sydney finds Bonnie's mutilated body in her apartment and calls the police.

Detective Jake Sousa reveals Bonnie communicated with her mystery date via a burner phone and there was no forced entry.

Jake privately tells Sydney that fingerprints from Bonnie's apartment match a second murder scene; both victims used the same dating app.

Sydney attends Bonnie's funeral and spots a man she believes to be her harasser Kevin among the mourners.

Sydney's nosebleed during a Cynch date draws the attention of the mystery man from before, who introduces himself as Dr. Tom Brown.

Tom and Sydney go on a successful first date; Sydney is unsettled to learn Tom works as a medical examiner.

Tom and Sydney have sex after their third date; Tom confesses he fell in love only once with a girlfriend who died young.

A restaurant patron greets Tom as Dr. Brewer, revealing that Tom gave Sydney a false last name.

A text message mix-up exposes that Tom has been communicating with Sydney exclusively through a burner phone.

While Tom showers, Sydney finds Bonnie's signature black scrunchie on his bedroom floor and realizes he was Bonnie's mystery doctor.

Jake confirms Tom's fingerprints match both murder scenes, but Tom provides airtight alibis for each killing and is released.

Sydney finds a bag of several locks of human hair hidden inside the toilet tank in Gretchen and Randy's apartment.

Gretchen is unmasked as the serial killer; she murders Randy and persuades Tom to run away with her.

Sydney's terrifying first date with Kevin sets the stage for a deadly investigation when her neighbor Bonnie is found murdered the very next day. Her ex-boyfriend Jake, now a detective, reveals that Bonnie's killer is a serial predator targeting women through the Cynch dating app. Just as Sydney fears for her safety, she meets the charming Dr. Tom Brown, who slowly wins her over despite a growing list of red flags. Discovering Bonnie's scrunchie in Tom's apartment shatters her trust and sends her racing to gather evidence, leading Jake to confirm Tom's fingerprints at the crime scene. However, Tom's airtight alibis redirect the investigation, and the real killer is exposed only when Sydney uncovers a bag of hair hidden inside Gretchen's apartment. The truth about Gretchen's obsessive murders tears apart Sydney's social circle and forces Tom to choose between justice and the woman he cannot live without.

The core murder mystery and Sydney's dangerous romance with Tom.

Tom finally speaks to his lifelong crush Daisy and walks her home; her father, the chief of police, invites Tom to dinner.

Tom watches his drunken father beat his mother and fantasizes about killing him; his friend Slug enthusiastically encourages the idea.

Tom kisses Daisy and lies that it was his first kiss, knowing no one alive can contradict him.

At a health fair, Daisy assigns Tom to draw blood; he struggles to hide his disturbing reaction when he pricks her finger.

Tom grabs a fire poker to defend his mother but hesitates; his father overpowers him and forces a promise never to interfere again.

The brutally murdered body of missing student Brandi Healy is found near the school, and Tom fears he will be arrested.

Allison reveals she saw Tom kissing Brandi and threatens to report him unless he breaks up with Daisy.

When Tom's father drunkenly threatens to sexually assault Daisy, Tom stabs him in the stomach and slits his throat.

Tom and Slug load Tom's father's body into a car trunk; Allison watches them from across the street as her dog barks at the car.

Tom and Slug bury the body at a remote location; Slug warns that Allison is a dangerous witness who must be dealt with.

During a police interview, Tom accidentally uses the past tense to describe Allison, arousing Chief Driscoll's suspicion.

Allison's mutilated body is found in the same river where Slug had previously suggested dumping Tom's father's corpse.

Tom's mother returns home; a bartender delivers Tom's father's phone and reveals he hasn't been seen; Chief Driscoll arrives at the front door.

Kevin appears in Sydney's professional video meeting under a false name, implying he has been watching her through her window.

Tom races to meet Daisy and finds Slug dead; Daisy confesses she murdered Slug, Allison, and Brandi to protect Tom and out of jealousy.

Long before Tom Brewer meets Sydney, his high school years are defined by his obsession with Daisy Driscoll, his abusive home life, and a string of murders that will follow him into adulthood. Raised in a household where his alcoholic father regularly beats his mother, Tom grows up associating violence with intimacy, setting the stage for the brutal act that will change everything. When a classmate named Brandi turns up murdered and another, Allison, begins threatening Tom's relationship with Daisy, the pressure mounts until Tom crosses an irreversible line by killing his own father. Disposing of the body with his friend Slug drags Tom deeper into deception, and when Allison's mutilated corpse surfaces, Tom can no longer trust even his closest companion. The investigation closes in as police and Tom's mother both grow suspicious, while Slug begins to view Daisy herself as a dangerous liability. The timeline culminates in a shocking revelation when Tom arrives to find Slug dead and learns that Daisy has been the killer all along, committing murder after murder to protect and possess him.

Tom's violent teenage past and the crimes that shaped him.

Tom's opening narration reveals he has loved Daisy since childhood but fears being alone with her might drive him to kill her.

Kevin tracks down Sydney and Bonnie outside their building and refuses to leave until Bonnie threatens to call the police.

Chief Driscoll questions Tom at school about missing student Brandi Healy; Tom lies and denies having a close relationship with her.

Tom and Daisy tell each other they are in love while walking home from school together.

Tom and Sydney share a kiss at the end of their first date, and Sydney gives him her phone number.

Jake calls Sydney to report a third victim with hair removed in the same pattern as Bonnie, confirming a serial killer is active.

Tom asks Sydney to delete her dating app profile and officially become his girlfriend.

Sydney realizes Gretchen's claim of working an all-nighter at her museum exhibit directly contradicts the alibi Gretchen gave police.

Sydney confronts Gretchen about her false alibi; Gretchen admits she lied to protect Randy and persuades Sydney to stay quiet.

Randy shows Sydney a small diamond ring and reveals his plan to propose to Gretchen, convincing Sydney she cannot report Gretchen's lie.

Sydney secretly slips Tom's open water bottle into her purse as evidence and invents an excuse to flee his apartment.

Tom pounds urgently on Gretchen and Randy's door, demanding entry and calling out for Gretchen using the name Daisy.

Tom agrees to keep Daisy's murders secret but vows never to pursue a relationship with her to avoid becoming like her.

A flashback shows Tom as a young adult imagining a future with girlfriend Cindy until she inexplicably stops answering his calls.

Sydney receives an envelope from Tom containing a lock of hair confirming Kevin's murder but decides not to show it to Jake.

From Tom's earliest warning signs in his opening narration to Sydney's final decision to conceal a murder, this pool traces the story's most pivotal moments of discovery and choice. The two timelines run in parallel, with Tom's teenage love story and Sydney's present-day investigation each reaching critical turning points that force characters to decide who they really are. Sydney repeatedly encounters information that should prompt her to act — Kevin stalking her, Gretchen's contradictory alibi, Randy's troubling history — but social pressure and romantic hope keep her from following through until she is nearly out of time. Meanwhile, Tom's past shows him making a series of compromises: lying to police, shielding Slug's crimes, and ultimately vowing to keep Daisy's darkest secret while trying to distance himself from her. The connections between the two timelines snap into focus when Tom pounds on Gretchen's door and calls her by the name Daisy, exposing the truth that has been hidden in plain sight. The pool closes with Sydney choosing to shield Tom from justice, a decision that echoes the novel's meditation on how love, danger, and survival can blur every moral line.