Beckett speculates that Hal unplugged the Wi-Fi so he could read any problematic emails before Doc (her parents share the same email address). She concludes that Hal sold pieces of his collection in a manner that raised “red flags” with the school. In the attic, Beckett finds a duffel bag of clothes, makeup, toiletries, and envelopes of cash. She remembers a lip print on the cup she found in the kitchen, and the shade leads her to conclude that Adalyn was staying here.

Trevor goes for a drive, and Mayhew appears with further details about Adalyn. As her wallet was wet, the authorities believe she drowned; she likely died in the quarry, and someone moved her. Mayhew mentions Delilah, but Beckett doesn’t believe that Delilah killed Adalyn then dragged her body through the woods to the construction site. Mayhew says someone saw Beckett at the quarry. Beckett repeats her timeline, and Mayhew mentions his young daughter, saying he’d do a lot for her if he had to.

After three hours, Trevor returns. He got rid of Delilah’s phone. Beckett summarizes her conversation with Mayhew: Adalyn died in the quarry and authorities believe that a Bowery moved her. Beckett wonders if Trevor moved the body during the night when he allegedly couldn’t sleep. Trevor promises that he was walking and thinking about how close he came to losing Delilah.

During dinner with Delilah, Trevor and Beckett try to “feign normalcy,” but Beckett addresses the police and her phone. Delilah says she lost it while she was in town with Sierra. On her laptop, she tracked it to Cryer’s Quarry. She went there alone at night, spotted a body, heard someone, and ran away. When she went back in the morning, the body was gone. As she thought someone was after her, she hid in the woods for a night. She never found her phone, and she didn’t put it in the dumbwaiter. More so, she wasn’t at Beckett Hall. Beckett wonders if the person on the camera footage is Adalyn, and she used Delilah’s phone to get in. Delilah spitefully brings up Beckett’s past, telling Trevor that Beckett wasn’t only Adalyn’s roommate: She might’ve assisted her.

The howling began, and Adalyn and Beckett saw the headlights of the truck. Micah and Charlie got out, and the truck drove away. Adalyn and Beckett ran, and Charlie and Micah followed. The plan was to “contain them” in the intricate tunnels with their complex locking system. Adalyn would run toward the exit at the storage barn, while Becket hid in a corner. Once Charlie and Micah passed, Becket would shut the door, automatically locking them in.

Beckett believes Delilah, but she’s not sure others will. The FordGroup sends her another odious text, along with a photo—the same picture of the mountain ridge that was on Delilah’s Instagram. As Beckett continues to get messages from the FordGroup, Beckett suspects someone was targeting Adalyn, so Adalyn isn’t the bully: She’s the victim.

Doc arrives on a redeye flight. Beckett updates Doc, and Doc reveals her role in Adalyn’s escape. She heard the sirens and thought Beckett was in trouble. She put on Hal’s size-10 boots and ran toward the campus, where she saw Adalyn with a bag. Adalyn claimed she lit a torch too close to the old president’s home. Adalyn told Doc about the key, the young men in the tunnel, and Beckett’s involvement.

Doc wanted to kill Adalyn; instead, she helped her escape to her wealthy father. Five years ago, Adalyn returned. Her parents died, and due to her new identity, she couldn’t get her inheritance, so she extorts Doc and Hal. They mortgage the house, and Hal, unethically exploiting his connection to Wyatt College, sells antiques. Every fall, Adalyn comes for more money, which is why Doc and Hal didn’t want Beckett there.

Beckett interviews Sierra at the deli, who confirms that Delilah was with her before she got lost in the woods. Sierra also saw Adalyn, who often came to the deli; she didn’t realize who she was until she saw Adalyn’s photo in the media. Sierra wanted to show Delilah the quarry before JW Enterprises turned it into a private park. Sierra thinks Adalyn followed Delilah, and Beckett believes Delilah reminded Adalyn of what Adalyn lost.

Beverly is also at the deli, and she reveals key details about Violet. Charlie and Violet were engaged. Violet was pregnant, and Charlie was the father, so Bryce is Charlie and Violet’s son—Joseph Wharton’s stepson. Charlie’s family gave the settlement to Violet, who married Joseph Wharton. He used her money to start JW Enterprises. He owned the house that burned down, but only now is he taking care of it. More so, when Beverly had a plumbing problem in the summer, he sent Bryce to make a report, giving him the chance to take Dill’s keys.

Beckett concludes that Bryce is the perpetrator, and Adalyn was trying to figure out who Bryce was while protecting Delilah. Delilah starts getting the old messages on her new phone, and one of them is from an unknown number, claiming that Cryer’s Quarry is “home base” for the howling. Outside the theater, Beckett sees Bryce eyeing Delilah. Though Bryce and Deliah are technically adults, Beckett considers them kids—though kids do “grown-up damage.”

Mayhew claims that the police can only put Delilah and Beckett at the quarry. If the quarry was home base, there should have been lots of students there too, unless Delilah was the lone student to receive the text. Beckett texts the FordGroup asking who they are, and they identify themselves as “the witness.” Beckett thinks Cliff is the witness, as he drove the truck the night of the incident. She confronts him at his home, but he’s mysteriously injured. She hears a creak and sees a shadow run toward the college.

Beckett assumes the shadow is Bryce. She thinks of Bryce as an angry child, and she concludes that Bryce and Cliff had a violent confrontation. When Beckett received the dropped phone call from Delilah, it was Adalyn calling for help.

Beckett follows Bryce through campus and into the tunnels, where she realizes she’s chasing Violet. Beckett dials Mayhew’s number, so he hears everything Violet says. Violet is the witness, so she drove the truck the night of the howling, not Cliff. Violet wants justice. Beckett admits that she didn’t mean to kill Micah and Charlie, and Violet says that Bryce didn’t mean to kill Adalyn. He was only going to “prank” Delilah, but Adalyn arrived, and Adalyn fell. Violet moved the body and tried to frame Delilah, then she put the phone in the dumbwaiter and took the mask.

Violet pulls out a matchbox; she wants Beckett to die how Micah and Charlie died. Beckett shows Violet that Fred Mayhew has been listening the entire time. Shocked, Violet runs out of the tunnels, where police wait for her.

Beckett ran to the fire, where a girl announced that Adalyn intentionally caused it. Unable to find Adalyn, Beckett returned to the tunnels, but she couldn’t open the door, and the smoke forced her to leave. She tried to convince herself that the deaths were an accident. Curled up on her bed, she waited for people to discover her role in the deaths.

Violet is led away while Mayhew arrests Beckett. Trevor is shocked, but Beckett expected it. While crying, Delilah hugs Beckett.

Beckett accepts a plea deal for involuntary manslaughter. Her sentence is three years, but her lawyer believes she’ll only end up serving half of the jail time. Beckett believes she “owed time” for Charlie, Micah, their families, and Adalyn. She dreams about not playing darts, stealing the keys, or shutting the doors, but then she likely wouldn’t have met Trevor or had Delilah. Trevor and Delilah wait for her to come home.