1996. A young boy wearing a pig mask walks into a sleeping couple’s bedroom. The woman springs up, startled, and tells the boy to wake up. It’s Cam, and he’s sleep-walking. He’s also wet himself. Cam’s mother scolds him, saying he’s too old for this behavior. As she leads him back to his room, Cam pushes her down the stairs. He takes off the mask and walks away, smiling, as Alan races down to his wife.
Back to the present day. Cam is carving a pumpkin with Sarah. After everything they’ve been through, it seems like things are finally at peace. Tomorrow is Sarah’s birthday: Halloween. Sarah heads to the gallery. Her customers all seem to be obsessed with her history and the murders, but hey, business is business! Robin arrives with an invite to his Halloween party, which is to be held in Justin’s honor. Sarah says she doesn’t want to go, but Robin won’t take no for an answer. Hopefully, no one gets poisoned at this one… Back at home, Cam’s doing shirtless pushups when Alan stops by to talk. He says he can’t imagine how upset Cam must be over June’s death, but Cam brushes it off, saying it’s been three months. Alan says he’s worried that Cam and Sarah may be rushing into something “unseemly.” Cam mentions that he knows about Alan’s own perversions, and Alan slaps him. Cam responds by knocking Alan to the ground. After Cam leaves, Alan starts rummaging through his room. He discovers the wooden box of murder mementos in the closet and opens it, horrified at what he finds.
Dylan stops by Sarah’s gallery and tells her he wants her back. Sarah’s not having it though, and she asks him to leave. Cam is watching this ordeal from across the street when he gets a text message from Alan asking him to meet at the church. At the church, Alan reveals that he knows that Cam is the Executioner, but that he will try to help him seek forgiveness. Alan begins to pray for Cam, but Cam grabs Alan’s neck and strangles him. Guess the Executioner wasn’t done killing after all.
Dylan writes an editorial in the Bulletin about how he ruined his marriage thanks to his own pride. Sarah meets Dylan and they take a stroll together. She admires his bravery and says she appreciates the sentiment, but she’s still upset about Dylan’s lies. Meanwhile, after hearing about Dylan’s story, Cam sneaks into Sarah’s house.. Later, Sarah’s packing up the house when she discovers the wooden box inside of a gym bag. She opens it to find newspaper articles about the murders, as well as the Executioner’s murder mementos. Oh no! Dylan’s meeting with the Bulletin team when Cam arrives with a squad of officers. Dylan is under arrest for the Executioner’s murders! Cam arrives at Sarah’s to comfort her. She doesn’t understand why Dylan left the box, almost as if he wanted to be caught. Cam reveals that he has feelings for Sarah and says he should have waited for her. They share a kiss… that leads to a steamy hookup. Jeez, Sarah, you’ve got terrible taste in men. Post-coitus, Cam offers to come back later after meeting with Dylan, though Sarah says she wants to be alone. At the police station, Cam presents the evidence to Dylan, but Dylan denies that he was the murderer. Cam says he’ll have time to think about his answers since Dylan will be in jail all night.
Back at home, Sarah’s going through her old camp scrapbook when she notices a photo of Cam with a sketch he made. Sarah realizes it looks familiar, and she compares it to one of the Executioner’s drawings. The similarity between the drawings is unmistakable. That night, Sarah heads to Cam’s empty house and sneaks in. Her snooping leads her to the basement, where she discovers a bloody basin and knife… along with Alan’s body parts stuffed in a bag. Sarah dials 911, but pauses for a moment before hanging up the call and picking up the knife. At the party, Robin gives a speech toasting Justin’s memory at his Halloween party before Sarah arrives. She approaches Cam and asks him to come outside. She pulls him out to a corner and starts kissing him, but Cam feels that something’s a little off. Sarah reassures him everything’s fine… before pulling out his knife and stabbing him in the stomach! At that moment, Robin comes to see what’s going on, and Cam musters the strength to pull out the knife and stab Robin in the chest! Sarah screams and Cam slashes her arm. She runs and Cam chases after her.
Meanwhile, a lawyer arrives to free Dylan from his holding room since he hasn’t yet been charged with a crime. Sarah runs down the street back to her house, as Cam stalks behind. She makes it inside and calls the police, but Cam breaks through the door. She locks herself upstairs, but as Cam pounds on the door, Dylan shows up and knocks Cam to the ground. Cam gets the upper hand and slams Dylan’s head against the ground as Sarah escapes down the stairs. Cam catches up to Sarah and throws her to the ground right where her mother died, stabbing her in the chest. As Sarah bleeds, Cam lies down next to her and tells her about the first time he saw her at camp and how he fell for her. He gets on top of her and says he’s sorry before raising his knife again. WHAM! Sarah hits him with the jar of Brenda’s ashes that had been knocked over nearby. Sarah picks up the knife and walks toward the door when Cam calls out her name. She locks the door and walks back to Cam. As she raises the knife above him, Dylan appears at the top of the stairs, pleading with her not to do it. He says she’s not a murderer, but she pleads for his help, and he grabs Cam. Sarah reveals that she doesn’t remember meeting Cam at all at camp, which he takes as a serious blow. Then Sarah stabs the knife into Cam’s stomach again and again, reminding him of all of the people she’s lost because of him. The police arrive, banging on the door. Sarah makes one last slice, slitting Cam’s throat and being sprayed with his blood as the police barge in.
Four weeks later. Sarah and Dylan stand outside the house as Robin walks up with a FOR SALE sign. Sarah and Dylan are finally leaving town, and it’s time to say good-bye. Sarah and Robin embrace before she gets in the car with Dylan and they drive away to start a new chapter of their lives. Back at the house, Robin brings in a family to see the place. The family’s daughter notices a cat around the side of the house and picks it up, telling it how pretty it is before she gleefully snaps its neck. She walks in to join her family, telling them that the house feels “perfect.” Oh boy…