Elin arrives at the corridor that leads to the special lift (or elevator) to the penthouse. She gets a text from Berndt informing her that they have intelligence on Laure Strehl. The word “intelligence” gives Elin the impression that Laure has been involved in something criminal. She notices sketches of human body parts line the corridor; “The effect is brutal. They look like images of amputation. Dismemberment” (235). The end wall is a vast mirror. As she approaches the lift, she thinks she sees movement in the mirror, but she brushes it off and heads up to the penthouse. She calls out for Laure, but she gets no answer. She feels she’s being watched. Then, the lift doors open, and she sees something on the floor of the lift that makes her knees go weak.

Elin finds Laure dead in the lift, her throat slit. The now-familiar black mask covers Laure’s face, and blood is seeping from her neck, soaking her blouse. Elin feels for a pulse, though she already knows that she won’t feel one. Laure’s skin is cool; she has been dead for a while, but not long enough for rigor mortis to set in. Elin begins to panic, realizing that the killer is probably still close by, but she remains calm enough to retrieve evidence. She blocks the lift doors with a chair and examines the body. Laure’s fingers have been removed, much like Adele’s, but this time they’ve been cut off with something like shears.

There’s no excess of blood in the lift, so Elin realizes that Laure wasn’t killed there. She texts Will that she’s found Laure, and she hesitates before typing she’s dead. She feels guilty for assuming Laure’s involvement in the murders. When she steps out of the lift, she almost steps on a glass box containing Laure’s fingers. The case hadn’t been there before, so Elin realizes that the killer had been on the lift while she was examining the body. She hears a noise, a strange breathing whistle sound, followed by a pull of air. She turns around and sees the killer, wearing the strange black mask.

Elin tries to fight her way out, but the masked figure is bigger than her and takes her down. The figure grabs her, reminding her of how terrified she felt during the Hayler case. Determined to escape, she manages to kick the attacker in the thigh. At that moment, Elin hears someone else come into the penthouse, and the attacker lets go, but pushes her to the ground. Elin’s head hits the ground, and the attacker pushes her face into the floor and tries to put a black mask on her, like the one on Laure. She moves to push the mask away. Then, she hears Will calling her name. The attacker leaves, and Elin picks herself up, her head throbbing from the fall. She feels tears sting her eyes as she realizes she’d been wrong: “This isn’t a crime of passion, of revenge over a fling gone wrong. It’s bigger than Laure. Something far bigger, and now she’s back to square one” (245).

Will tends to Elin as she gathers herself after her encounter with the killer. Elin is in shock and tries not to think about how close she’d come to dying: “I could have lost all of this, couldn’t I? Me and Will… if the killer got their way…” (246).

Elin realizes that Will was only able to save her because he got her text message: a message that she shouldn’t have had time to send. She realizes that the killer had to come into the penthouse another way because of Laure’s body being in the lift. She asks Will how he came in, and he explains that when the lift wouldn’t come, an employee showed him to the stairs. She realizes that the killer made a mistake and “if the killer has made one mistake, there might be another” (248). Will begs her to leave the investigation for the police, but Elin feels that she can’t. She believes that trying to kill her means that the killer wanted her out of the way because they’re planning something else. 

Elin photographs Laure’s body, noting that the killer was hurried, but ruthless in the way they killed Laure. The lack of defensive wounds on the body suggests that the killer uses a sedative on their victims. Adele mostly died from the drowning, while Laure’s throat was cut. Also, unlike Adele, Laure’s fingers were cut without the wounds being sutured. Elin makes note of the elements that are similar: The black masks, the finger removal, and the glass box, which is just like the ones in the hotel displaying medical items from the old sanatorium.

Elin gets a call from Berndt explaining what they found on Laure when they ran her background. Elin tells Berndt that Laure is dead and that she had a run-in with the killer. Berndt tells her to prioritize her safety and that of the people in the hotel: “Elin, the priority now is keeping you, the staff, and the remaining guests safe. Once you’ve taken the photographs, please stay in a safe and secure location” (254). Elin asks him when the police will be able to arrive, and he isn’t sure because the weather hasn’t cleared up.

After talking to Berndt, Elin finds a USB memory stick disguised as a lighter in Laure’s pocket. Elin realizes that this is the killer’s second mistake.

Cecile and Lucas join Elin and Will in the penthouse to deal with the discovery of Laure’s body. Cecile suggests Elin interview everyone again, and Elin reminds Cecile that she and Lucas will also need to give her their alibis. Elin asks if she can see the CCTV again, but Cecile tells her the whole system went down the previous night.

Berndt calls back and tells Elin that the police won’t be able to get to them for at least another day. They have people trying to get to the hotel on foot, but that will take a few days as well. Realizing they’re on their own, Elin recalls the 2011 terror attacks in Norway, in which a man shot teenagers who were gathered on the island of Utoya for summer camp, killing 69 people before the police were able to reach them.

Lucas asks Elin about the copper bracelets in the glass box. He points out the engraved numbers on the bracelets, and Elin realizes that the numbers must be significant in some way. She takes pictures of them, but as she does, she notices that Lucas takes a troubled glance at Cecile. 

Will and Elin start down the stairs from the penthouse a while after Cecile and Lucas. As they walk down the stairs, they hear Lucas and Cecile arguing in French. Will translates for Elin as best he can. Cecile tells Lucas that what happened to Laure isn’t a coincidence: that he should reveal something. Elin isn’t sure what to make of them. She decides that before she digs any deeper, she needs to tell Isaac what happened to Laure.

Elin goes to tell Isaac that Laure is dead. Isaac is angry with her for suspecting Laure in the first place: “She was looking forward to getting to know you again, Elin. You know that, right? She never understood why you lost contact. She tried to write, call…” (264). He compares Elin to their mother, again, saying that she was selfish and only thought about herself. Isaac, weeping over the loss of Laure, feels guilty that he didn’t look harder for her, and he blames himself for her death. Elin tries to tell him that it isn’t his fault, but he’s in shock and isn’t really hearing her. Before she leaves, she notices something in the fireplace, which Isaac says is some rubbish from his bag. Elin thinks it might be a photograph, but the fire burns it before she can see it.

Elin returns to her room and checks the memory stick on her laptop. She finds scanned documents from Gotterdorf Klinik, dated 1923. The documents are in German, and Elin can only make out the words that are similar to English. She uses Google Translate to find out that Krankengeschichte, a word listed under “name” and “birth date” on the documents, means “clinical history” (267). The documents are otherwise redacted. She notices that the records all have ID numbers listed, which are five-digit numbers just like on the copper bracelets.

She cross references the numbers against the bracelets and finds a number that matches with a bracelet found near Adele: 87534. Elin Googles the clinic and finds out that it is a German psychiatric facility. Elin finds a number and calls the clinic. The receptionist tells her that she can’t reveal any medical information about a patient, but she agrees to tell Elin what type of information they contain. Patient files at their clinic contain information about their diagnosis, treatments, and medications, as well as their response to treatment. Elin asks if she can verify that the files are authentic, but when she gives the receptionist the number, she finds that the files have been removed from their digital database. 

The receptionist is alarmed and hurries off the phone. Elin realizes that whatever was in those files must have been serious and that someone must have wanted them buried. She wonders why Laure even had copies of the files in the first place.

She recognizes that the killer has a signature, noticing four elements to each murder: the glass display boxes, the removal of fingers, the copper bracelets, and the black masks placed on the victims. She realizes that she’s been focused on the interpersonal relationships between the people in the hotel and had ignored the medical aspect. She decides that the murders aren’t about the hotel, but about the sanatorium.

Will comes back to the room and tells Elin that the snow is forecast to get worse over the next few hours, increasing the avalanche risk. Elin tells him what she found on the memory stick. She explains what she thinks the connection is between the murders and the medical files that were on the memory stick. Elin realizes that she needs to check the archive room again.

Cecile lets Elin into the archive room. Elin mentions that Laure told her about the plans to make the room into an official archive, and Cecile reveals that the project got pulled because some of the details of the sanatorium were too graphic: “One of the treatments was a pneumothorax—collapsing the lung. They did this by either introducing air into the pleural cavity, or permanently collapsing it by removing part of the rib cage…” (280). A lot of the patients didn’t survive, and Lucas thought guests would not enjoy knowing that.

Elin notices that Cecile always talks about what Lucas thinks and assumes that Lucas is a controlling force in Cecile’s life. She decides to tell Cecile that she heard them arguing in the corridor to get a clearer picture about the two of them. Cecile reveals that they were arguing about Daniel Lemaitre’s body, which was found on the mountain.

Cecile reveals that Daniel’s remains were mutilated, like Adele’s and Laure’s, but worse. Elin thinks the murders must be connected, but because of the time between them, she can’t figure out why or how. Cecile explains that Lucas didn’t want her to know because he was trying to contain the situation so as not to destroy the hotel: “‘This place… he’s never said it, but I think it’s about exorcising those ghosts. It was the impossible project. Someplace everyone said could never be resurrected.’ Cecile shrugs. ‘Like him. No one thought he’d become what he has.’” (283)

Elin thinks there’s more to it than Cecile is letting on. She asks about Lucas and Daniel’s relationship. Cecile says they hadn’t been really close in adulthood, but they were friends in childhood until Lucas got sick, and they grew apart. They got into a fight a few days before Daniel’s disappearance.

Someone knocks on the door, and Cecile answer it to find a young hotel employee, Sara, standing there. Crying, she tells them that she can’t find Margot and hasn’t seen her since the previous night.

Sara says she and Margot were sharing a room, and when she got up in the morning, Margot was gone and there looked like there was a struggle. No one has heard from Margot. Elin believes that Margot is the next victim.

Margot’s side of the room is indeed suspiciously messy, “as if she’s been dragged from bed” (287). Sara says she didn’t hear anything because she uses sleep aids. She tearfully worries that whoever killed Adele has Margot. Sara tells Elin that they had dinner with the staff, then went to bed. When she woke up, Margot was gone.

Elin questions the young man guarding the corridor about what happened. He says he only saw guests and staff going to their rooms. Elin notices the French doors at the back of Sara and Margot’s room have small marks on the wood and that the killer must have come in that way. She notices imprints in the snow that are about the size of a human body and assumes the killer dragged Margot out.

Elin puts on her coat and goes outside the way she thinks the killer went, even though she knows that she probably should alert Berndt of the new developments. Waiting might mean Margot dies. She tries to hoist herself over the balustrade, wondering how the killer did this while dragging Margot’s body. She finds herself in the middle of heavy snowfall. She hears an avalanche coming and runs back towards the hotel. The avalanche just barely misses her. Once the snow clears, she follows the trail that the killer left around the building, but it stops at the front entrance. Inside, the floor is polished and clean, with no sign that anyone had come in from the snowstorm.

Elin realizes that Margot’s phone wasn’t in the room and that it might be on her. 

Elin tells Sara that they might be able to find Margot if they track her phone. Cecile expresses concern for Elin, implying that going out into the snowstorm by herself to look for clues was reckless. Elin insists that she had to, but her tone is more defensive than she intends. Cecile subtly questions Elin’s judgment, and so Elin changes the subject and asks Sara if she knows Margot’s iCloud login information so that they can use Find My iPhone to track her phone. Sara says that Margot keeps her passwords in her diary.

They find the diary in Margot’s bag, and Elin logs in to Margot’s account from her own phone. Using Find My iPhone, they find that Margot’s phone was active 40 minutes ago somewhere in the hotel.

Elin asks Cecile where the point on the phone is in the hotel, and Cecile reluctantly tells her it’s near the spa; the generator rooms. She doesn’t think Elin should go immediately, and Elin wonders why Cecile isn’t treating the situation with a sense of urgency. Cecile reveals that Lucas found out that Elin was on an extended leave from her job and that he doesn’t want her to keep investigating. The Carons want Elin to wait for the police, but Elin knows that the avalanches mean that the police won’t get to them any time soon. Angered and shamed, and she goes back to her room.

Elin vents to Will that the Carons don’t trust her. He agrees that maybe they should wait for the police, but Elin balks, reminding him that there had been a second avalanche. She thinks that if they wait, Margot will die. Will agrees, but he refuses to let Elin go alone. 

Elin and Will walk past the spa reception desk on their search for Margot. Elin remembers Laure’s first tour of the spa area and blinks back tears: “This is for Laure as much as it is for Margot” (303). They check the changing rooms and the pool area, and Elin begins to worry that the killer has simply ditched the phone there. The last place they search is the maintenance room, and Elin doesn’t expect to find anything there. As soon as they walk in, the lights go out. Will tells Elin to use her phone’s flashlight. Will suggests that someone has cut the lights on purpose and that they should leave, but Elin tells him to go while she looks around. He refuses to leave her, and they push forward.

Elin hears a noise and shines her light. There, she sees Margot, laying on the floor, not moving. She is bound and dirty, apparently from being dragged. Elin tries to untie her, but as soon as she tries, Margot hauls back and kicks Elin in the knees. Elin collapses and cries out in pain. At first, she thinks Margot has mistaken her for her attacker, but she quickly realizes she’s wrong.

Elin realizes that Margot was never actually a victim: “I’ve got this wrong, again. All my theories, ideas, about Lucas, Isaac, they’re wrong” (308). Margot stands to her feet, her binding falling off. Elin accuses her, and Margot admits to setting the whole thing up: “Don’t worry. You made the same mistakes anyone would, human mistakes. The ego always wins. It’s a weakness in everyone, the desire to know the most, be the hero, the one to save the day. It’s why you did the job you did” (309).

Margot pulls out a knife and reveals that she was against the hotel opening, because of its past, and she never meant for Elin to be involved. Margot moves to stab Elin, but Elin dodges her blow. Margot goes for her again, but Will rushes her and pushes her away. Elin drops her phone, losing the only light she has. She listens in horror to Margot and Will scuffling in the dark. She hears someone run away, and she knows it’s not Will. She calls to him, but she gets no answer. She scrambles to find her phone and turns the flashlight back on. She sees Will lying on the ground, bleeding out. She rushes over to him and clamps her hands over the wound on his stomach, “a narrow, deep slash a few inches below his navel” (311), trying to stop the bleeding.

Will, gravely injured, lays in their bed, pale and weak from loss of blood. Elin blames herself for putting him in harm’s way. With no access to medical treatment, Sara, who is also a nurse, has done her best to try to keep him comfortable and stable, but his injuries are serious, and he’ll need to get to a hospital as soon as possible.

Isaac comes to comfort her, and Elin breaks down in front of him, and she starts to have a panic attack. He brings her her inhaler, and once her breathing stabilizes, she admits to him that what she’s dealing with isn’t really asthma, but anxiety, which has been worse since their mother’s death and the Hayler case, both about a year prior. Elin brings up Sam, again, and Isaac tells her that she can’t keep bringing Sam into everything.

Elin finally accuses Isaac of killing Sam, telling him about her flashbacks. He tries to back away from the subject, but Elin pushes, accusing him of lying about going to use the bathroom when Sam fell. She only pulls back when she notices that he doesn’t seem to be defensive. Instead, he’s looking at her with pity: “I wasn’t there when he died, Elin. It was you with him, not me” (316).

Isaac tells Elin the full story for the first time. She had come back to watch over Sam while Isaac went to use the bathroom. When he came back, she was just standing there in shock, and Sam was already dead. He tells her that the doctors said she couldn’t have saved Sam if she’d tried because he died as soon as he hit the rocks. Elin is reeling from the revelation, but she asks Isaac to tell her the whole story. She asks about the blood on his hands, which he reveals were from pulling Sam out of the water because he was bleeding from his head. Elin can’t believe that she watched Sam die and did nothing. Isaac tells her that she must have put up mental barriers to protect her from what she saw and to keep her from feeling like it was her fault.

Elin asks Isaac to leave. Once he’s gone, Elin recalls incidents from her childhood that lead her to believe her mother blamed her for Sam’s death. She dissolves into tears at the memory, guilt overwhelming her.