Early the next morning, Courtney leads the children out of the motel. The police car assigned to watch them sits empty. They walk single file along the gravel shoulder of a two-lane highway toward the police station, where Courtney intends to speak with Detective Evans. Cass asks questions, and Wyatt glances back at Courtney, sensing she is hiding something. As cars approach, Courtney stiffens, imagining Elliott leaving the cottage after she fell asleep, killing Emily and Nolan, taking Reese, and rowing out to the deepest part of the lake to drown her. She wonders if the blood on Elliott’s shoes belonged to Reese, Emily, or Nolan. When Wyatt spots another approaching car, Courtney ushers the children into the grass near the trees for cover and considers telling them to run.

Events unfold rapidly. Reese tries to grab Emily’s hand again but misses as Emily walks to the door. Reese covers her face as the deadbolt turns and the door opens. Emily asks a stranger if she can help him. A man says the name Kylie. Reese realizes it is not Mae but someone Emily does not know. The man steps inside, his eyes locked on Reese, and tells her he and her mother have been searching for her for years. Emily firmly says he is mistaken and this is her daughter, Reese, but he shrugs her off and pushes her into the coffee table. He sweeps Reese into his arms, insisting Emily stole her. When Emily tries to pull him off Reese again, the man elbows her in the face, causing her nose to bleed. Emily grabs Wyatt’s baseball bat and swings, but he catches it, tugs it from her blood-slick hands, and drives the knob into her stomach. She collapses and tells Reese to run while grabbing his ankle.

Reese runs to the screened porch and tries to tear through a screen to escape. She hears the bat strike bone as the man attacks     Emily, then throws herself under the bed. He enters the porch, sets down the bat, and examines the torn screen. Through the open door, Reese sees Emily struggle and fall. The man crouches and grabs Reese’s ankle, pulling her out as she kicks. Emily enters, bleeding from her head, and manages to pull his hands off Reese, but he flings her to the ground, picks up the bat, and swings. Emily becomes still. Upstairs, a door opens and Nolan calls for Emily. The man tightens his grip on the bat and moves toward the stairs. Nolan, squinting without his contacts, sees a stranger approaching and stumbles back, saying one word before the man attacks. Reese covers her ears and curls around Emily’s body, begging her to wake up.

At the police station, Courtney shows Detective Evans the searches on Elliott’s iPad and the Facebook post claiming to have found Kylie Matthews. She observes Cass nudge Mae under the table. Mae begins to cry, and Courtney realizes the tears stem from guilt, not grief. She remembers the girls used Elliott’s iPad the night of the murders and notices a misspelling in the post. Courtney confronts them, and Cass admits they made the post as a joke. Cass confirms she and Mae took the picture of Reese by the pool, not Elliott. Detective Evans investigates the “Help Find Kylie Matthews” Facebook page, which is owned by Sam and Joanna Matthews. He examines the post from less than a week ago claiming Kylie was found alive. He abruptly stands, grabs his keys, and says he is going to speak with the Matthewses. He denies Courtney’s request to accompany him, telling her to stay put and that he will bring Reese back if she is there.

Sam Matthews pulls Reese by the hand through a field, gently insisting Emily and Nolan were bad people who stole her. When she falls, he helps her up kindly. Reese thinks of things she could have done differently, like using Daniel’s knife. She pulls out her phone, but its light alerts Sam. In the glow, she notices blood on his face. He reacts abruptly, frightening her into collapsing, then speaks gently as he takes the phone. They reach a parked car with child locks engaged, and he drives to a house with the porch light on. Inside, a woman in pajamas enters and is shocked to see Sam covered in blood. Sam joyfully tells his wife that he has found their daughter, Kylie. Joanna looks at Reese and states flatly that she is not Kylie. Sam, in disbelief, points to a family photo over the fireplace and tells Reese to show Joanna the necklace from the picture, but Reese no longer has it. Joanna insists she would know her own daughter. Sam finally realizes his mistake and breaks down sobbing. He and Joanna discuss what to do with Reese, concluding they cannot let her go because she witnessed the murders. They lead Reese to the basement and lock her inside a crawl space.

Courtney calls Elliott and tells him to come to the police station, feeling guilty for having suspected him. She watches Cass and Mae play tic-tac-toe, wondering when the gravity of their actions will sink in. She remembers Joanna Matthews implying Daniel was responsible for harming both Kylie and Reese—their girls—and realizes Joanna intentionally misled her. She wonders if Reese was hidden in the Matthewses’ house when she visited or if they killed her after realizing she was not Kylie.

Reese describes her captivity in the cramped crawl space, where she is given food and water and occasionally let out to use the bathroom under guard. One day, the hatch opens to reveal a police detective with red hair who asks if she is Reese Crane and says they have been looking for her. In a hospital room, Aunt Courtney confirms that Emily and Nolan are dead. Reese tells Courtney she already knew because they would have been the first to see her if they were alive. Reese tells Courtney and a police officer that she thinks she knows where the Matthewses’ daughter is. She explains that she saw Ms. Dahl, the resort owner, placing flowers on an unmarked grave in the cemetery near the resort, suggesting Kylie Matthews might be buried there.

Courtney watches Ms. Dahl’s interrogation on a monitor. Ms. Dahl tells Detective Evans she helped Daniel Clarke out of guilt over his mother’s death. She claims that on the night Kylie Matthews disappeared, she was walking in the woods and saw Daniel in the cemetery. She says she recognized him by his tattoo in the moonlight and watched him dig a grave and place a girl’s body inside. The next morning, she returned and tidied the gravesite, planting grass seed to hide it. When Evans tells her she is an accessory after the fact, she dares him to arrest her. After the interview, Evans tells Courtney that Sam Matthews confessed to the murders and kidnapping. She learns the necklace Reese wore, which spelled daughter in Morse code, belonged to Kylie and was a key factor in Sam’s delusion. Elliott is at the hospital with Reese. Detective Evans drives Courtney and the kids to the resort to pack. On the way, he says Ms. Dahl’s testimony should be enough to reopen the investigation into Kylie’s death but maybe not to convict Daniel. At the cottage, Evans shares that the medical examiner confirmed Emily had defensive wounds and fought back hard. Before leaving for the last time, Courtney stands in the doorway and remembers Emily laughing in the kitchen.

Outside the hospital, Courtney asks if she can text Detective Evans to check in. Courtney hugs him and thanks him. As he drives away, Josh feels relief that Courtney still sees him as one of the good guys. He reflects on Ms. Dahl’s testimony, knowing she was mistaken. It was Josh, not Daniel, whom she saw burying Kylie’s body.

At home, he looks in the mirror and pulls up his sleeve, revealing his own King Cobra tattoo. He recalls growing up across the street from Daniel Clarke and being part of a teenage group in which he, Daniel, and two others all got the same tattoo. He admits to himself that he accidentally killed Kylie Matthews. Kylie was his younger sister, Abby’s, friend, and the two girls mocked him, though Abby later told him Kylie actually liked him. He followed Kylie on her bike in his car to scare her as a lesson. He swerved at her; she laughed at first, then got scared and insulted him. He swerved closer and clipped her back tire. She fell into the street, and he could not brake in time, running her over. In a panic, he put her body in his trunk and drove to the cemetery to bury her.

After Kylie’s death, Josh changed his life, cut off his old friends, and joined the police academy to atone. He recalls catching Daniel robbing his house years later and letting him go. In the present, he decides he no longer owes Daniel anything. He plans to arrest Daniel the next day and use Ms. Dahl’s mistaken testimony to frame him for Kylie’s murder. He rationalizes that Daniel is a bad person who deserves to be off the streets. He repeats his mantra, trying to convince himself he is one of the good guys.