Emily opens her door expecting Sam, but it’s Aaron. She immediately warns him that he needs to leave. Aaron says he isn’t there to hurt her; he just wants to talk. He tries to explain that someone else is using the name Chimera and is responsible for what happened at the warehouse, and that they may both be in danger. Emily is skeptical and demands that he leave. She shuts the door in his face and makes sure to lock it.
Emily pulls out her laptop to look up some of her old colleagues and finds that several of them have died under mysterious circumstances. When she opens the door for Sam, he immediately notices that she is distraught. He hugs her tightly to comfort her.
Emily explains everything to Sam and tells him she needs to leave town to try to end things before they get more dangerous. Sam offers to join her, but Emily says he can’t because he is a cop. She quickly packs her things, loads up her car, gives Sam a hug, and drives off.
Eleven months later, Ruth and Richard are arguing in the driveway. Richard’s wife, Helen, comes out to mediate, but Ruth gets back in her car and drives off angrily. Richard tells Helen he needs to finish the Christmas lights on the house, and she reminds him not to overdo it. Later that night, Richard climbs his ladder onto the roof to work on the lights. While he is up there, someone climbs the ladder behind him and detaches it from the roof. Richard notices the person and says, “You really shouldn’t be up here.”
Ruth arrives and notices the ladder lying in the driveway. She looks around and finds her dad dead on the ground at the side of the house, a red oven mitt in his hand. While she is tending to him, Helen comes out to see what the noise was. Ruth immediately blames her for what happened to Richard.
Sam arrives at Sue’s to welcome Violet home from her gap year traveling around Europe. They start to catch up, but Sam gets a call and has to leave.
Sam arrives at the crime scene and introduces himself to Ruth before asking her some questions. He learns that Richard used to be a roofer and that he and Ruth’s stepmom, Helen, had been married for just about a year.
A concerned neighbor stops by to see what is going on and introduces himself as Albert Dobbs. He warns Sam to shield his eyes for a moment. Just as the clock strikes 7, all the Christmas lights switch on, illuminating the whole house. Albert jokes that it’s like living next to a supernova.
Sam notices one of the upstairs windows cracked open and goes to talk to Helen. She explains that she usually leaves the window open when the fireplace is on so she doesn’t get too warm. Sam also notices a single red mitt in the room and hears Helen mutter to herself that she never should have married Richard. Sam tries to ask Helen more questions, but she seems overwhelmed, so he says he’ll come back tomorrow.
Back at the diner, Violet and Sam catch up over hotcakes. Sam notices Ruth walk in, and Sue mentions that Ruth has been coming in regularly to order coffee and work in a booth all day.
Helen comes into the station for more questioning. She explains that she was making wreaths while Richard was on the roof and only stepped outside to collect more pine branches. Sam asks how Richard could have ended up with one of Helen’s red mitts, but Helen isn’t sure. From their conversation, Sam gathers that Ruth and Richard argued earlier that day and that Ruth has been especially cold toward them for the last month. Sam offers to arrange a ride home for Helen, but she says the mayor already has a car coming to pick her up. She explains that the family became close with the mayor because Richard has been working alongside him as the town’s Christmas Chairman.
While driving, Sam calls the mayor’s office to set up a time to talk with the mayor about Richard. He notices the lights are on at Under the Mistletoe and stops to see whether Emily is back.
He walks inside to find June straightening things up. Just as Sam asks June to tell Emily he stopped by, Emily walks into the shop. Sam greets her with a warm hug. They agree to meet up later to catch up, and Sam leaves to continue investigating Richard’s death.
Sam heads back to the diner to speak with Ruth. From their conversation, he learns that Ruth moved back to town out of concern for her father after receiving an anonymous text warning that Helen was dangerous. She brushed it off at first, but after noticing her dad acting strangely, she began to think there might be some truth to the message. Ruth explains that her argument with her dad earlier in the day was a silly disagreement about taking precautions while working on the lights.
Emily puts up an “Everything Must Go” sale sign outside the store. Violet arrives and asks if she can work at the store again to save up money after her travels. Emily immediately agrees. June mentions that a package arrived, and Emily is confused because she didn’t order anything for the store. They open the mysterious box to find a beautiful wreath inside. Emily decides to head to the wreath-maker to make sure it was paid for and wasn’t sent by mistake. On her way over, she runs into Brooke, who mentions that she is running for Christmas Chairman now that Richard has passed. Emily learns about Richard’s case and remembers that he recently married Helen, the same wreath-maker she was on her way to visit.
Emily arrives at Helen’s home and offers her condolences. Helen says the wreath was complimentary. She then opens up to Emily, sharing that her home doesn’t feel the same without Richard. To her, he was home, not the house. On her way out, Emily waves to Albert next door, who quickly heads back inside.
Sam and Emily make plans to meet up for dinner to catch up. Emily mentions that she stopped by Helen’s and noticed some odd things. Sam jokes that she has barely returned and is already getting involved in his investigations again. They are interrupted when the mayor arrives for his meeting with Sam. Emily is dumbfounded to find out that the new mayor is Famous Ray, now Mayor Pemberton.
Ray says he can’t think of anyone who would want to kill Richard. Their conversation is interrupted by a commotion outside Sam’s office. A young man named Wes is urging the officers to arrest Helen. When Sam asks who he is, Wes claims that Helen used to be his stepmother and that the same thing happened to his father. He urges the police to arrest her before she disappears again.
Sam talks to Wes in his office. Wes explains that his father died when Wes was 11, after a combination of pills in his system caused him to lose control of his car. When Wes got older, he became a journalist and tracked Helen down again after her next husband died of carbon monoxide poisoning. Wes was surprised when he later received a letter from Helen apologizing for how she left things with their family. He traced the letter and tracked her down, concerned that she was going to strike again.
Emily returns to the store and thanks June and Violet for helping her get things set up again. She flips the sign and reopens the store for business. June and Violet suggest that Emily run for Christmas Chairman against Brooke. Emily brushes off the idea, noting that it takes 500 signatures just to get on the ballot. After Emily leaves, Violet and June plan to collect 500 signatures for her.
Sam and Emily meet up at Sue’s. Emily shares that she isn’t sure about Helen’s past, but she is convinced that Helen’s grief over Richard is real. Sam tells Emily he understands the importance of what she has been dealing with over the last year, but he wants to know where they stand. Emily says the circumstances have changed, but her feelings haven’t. Sam says he feels the same, and they agree to enjoy the holidays together.
Emily decides to dig further into Helen’s past to distract herself from how much she has missed everyone in Fletcher’s Grove. She has a flashback to her intelligence training, when she met Thomas Chase, who asked to have her join his field ops team. The door buzzes. It’s Violet. Emily buzzes her in and is surprised to find Violet, June, and Sue at her front door with drinks and food to celebrate her return.
Ray asks to meet with Emily to talk about Richard’s death. He is convinced it was just a freak accident and that Helen wasn’t at fault. He recalls how highly Richard spoke of her and can’t imagine she was responsible. He hopes Emily will convince Sam to close the investigation before the town starts to worry.
Emily decides to check on Helen. She still believes Helen is innocent, and she doesn’t judge her for her alleged past because she has a dark past of her own. To Emily’s surprise, Helen opens up about her past and admits to killing her previous husbands. When Emily asks her to explain, Helen says she blames herself for not stepping in on her first husband’s pill abuse. She also mentions that her second husband asked her to replace their carbon monoxide alarm, but he died while she was away on a trip, before she had the chance. She sees both deaths as preventable and blames herself. Helen explains that she warned Richard not to marry her, but he agreed the deaths weren’t her fault. Since then, her stepson Wes has been after her and even nicknamed her “The Grim Wreather” in one of his articles.
Sam arrives at Helen’s house to continue his investigation. He bumps into Emily, and she doubles down on Helen’s innocence. She notices Albert eavesdropping on their conversation again and points him out to Sam.
While Emily is at the store, Brooke bursts in and angrily confronts her for running against her for Christmas Chairman. Emily is confused at first. After Brooke leaves, she turns to Violet and tells her that she appreciates the nomination but can’t accept it.
Emily runs into Ruth and Wes at the diner. Wes makes a scene, yelling that Helen Smiley is a killer.
Emily meets with Sam to report what happened with Wes at the diner. While they are in his office, he receives new forensic evidence showing a second footprint on the roof, meaning Richard wasn’t alone. Sam opens the case as an official murder investigation.
Emily bumps into Brooke while she is campaigning on the street. Brooke taunts Emily for running against her and claims Emily isn’t as spirited as she is. Stung by the insult, Emily decides to run for Christmas Chairman after all. Then Sam calls and asks her to join him on another trip to Helen’s house.
On their way to Helen’s house, Sam is alerted to a 911 call about a home invasion nearby. They arrive at Albert’s house. Albert is outside on the porch and tells Sam the intruder is still inside. Sam orders the intruder to step out with their hands in the air. Helen emerges from the shadows of the house with her hands up.