Did you read The Sanatorium by Sarah Pearse and have ALL the questions about the ending? And what’s with that epilogue – who is following Elin around the Sanatorium? Come check out my spoilers and plot summary for The Sanatorium and then let’s discuss this baffling case of multiple murders in a Swiss alps resort and the equally baffling ending! Check out this Spoilers and Plot Summary for the Sanatorium!

The Sanatorium by Sarah Pearse. Published February 2, 2021 by Pamela Dornan Books.
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The plot summary below will contain spoilers. If you want to read my spoiler free review of The Sanatorium, you can find it here.
TABLE OF CONTENTS FOR THE SPOILERS AND PLOT SUMMARY FOR THE SANATORIUM
- Plot Summary for the Sanatorium
- Who was the killer in the Sanatorium?
- WHAT WAS THAT FINAL CHAPTER? The Sanatorium ending, explained — or at least the possibilities explored!
- BREAKING NEWS: Yes, there will be a sequel to The Sanatorium. Elin will be back! Will we find out who’s is stalking her? Maybe not…
Spoilers and Plot Summary for the Sanatorium by Sarah Pearce
Elin and Will arrive at Le Sommet, a resort in the Swiss Alps. She’s a British police officer and they are meeting her brother, Isaac, and his partner Laure. Elin and Laure knew each other growing up, and now Laure is the assistant manager at Le Sommet and she and Isaac are engaged.

Adele, a hotel cleaner at Le Sommet, finds a copper bracelet outside one of the rooms. When she leaves work she is attacked by someone in a gas mask.
Isaac and Laure show Elin and Will around the hotel. They point out Lucas Carron, the hotel owner and his sister Cecile, who helps manage the resort. They mention that the hotel’s architect, Daniel, was a friend of the Carron siblings who disappeared while the hotel was being planned.
The next morning Isaac says he can’t find Laure. Then a skiier discovers the body of Daniel, the missing architect.
Elin talks to Isaac about where Laure could be.
Elin also tells her brother about a case that is preoccupying her: the murder of two teenage girls. An anonymous tip led the police to a suspect: Mark Hayler. Elin went to question him and he ran. She chased him along the beach and into the surf and he hit her with a rock and got away. After that, she took a leave from work.
Elin sees what she thinks is blood on the rug in Isaac and Laure’s room, but Isaac says Laure cut herself shaving.
Elin seems slightly suspicious that Isaac has something to do with Laure’s disappearance. She tells Will that she thinks Isaac might have killed their brother Sam, who drowned when Sam was eight, Elin was twelve, and Isaac was ten.
Sam’s death was ruled an accident, but Elin has had flashbacks about seeing Isaac with blood on his hands.
This plot point will be important later:
Will convinces Elin to try to relax at the spa. As Elin leaves the pool area alone, someone pushes her from behind into a freezing outdoor plunge pool. Flashing back to Sam’s death, she panics but manages to climb out. Will tells her she must have slipped.

The resort is evacuated due to the storm and avalanche risk. Isaac refuses to leave as Laure is still missing. Adele is found dead in the pool.
Due to a small avalanche blocking the road, the police can’t come, so Elin secures the scene and collects evidence on their behalf.
People tell Elin that Laure and Cecile seemed at odds. Lucas confesses that he and Laure had a short fling and that he had been receiving anonymous, threatening notes.
Someone wiped much of the resort’s CCTV footage, but there is footage showing that Laure was following Elin at the spa. She wonders if Laure is the one who pushed her and is also the killer of Adele and Daniel. Files from Laure’s computer reveal that Laure was providing information to a journalist on an expose on the resort.

Laure texts Elin asking to meet. Instead, Elin finds Laure’s body. They also find a flash drive and a copper bracelet at the scene. The hotel CCTV cameras are down and the weather is still too bad for the police to get to them. Elin thinks Lucas and Cecile are acting strangely.
Elin connects numbers engraved on the copper bracelets to some old medical files on the flash drive.
Another hotel employee, Margot, goes missing. Elin tracks her phone within the hotel and she and Will go looking for her. Margot escapes and Will gets stabbed.
Isaac and Elin discuss Sam’s death. Isaac says it was an accident and that Elin was the one with him at the time. Elin finally remembers the details of her brother’s death and in doing so recalls that Margot dropped something when she was struggling with Will.
She finds what Margot dropped – an envelope with old medical records and gruesome old photos of medical experiments on women. One entry has the same number as the copper bracelet. Elin suggests that Margot was avenging the deaths of five relatives who were sanatorium patients in the 1920s.

Elin finds a secret tunnel. She and Lucas go to investigate and find the killer’s lair. Margot is there, injured and dying. She turns to Lucas to say that Margot was working with someone else, but Lucas has disappeared.
Elin goes to Cecile for help and they search Lucas’s office for clues. Cecile confesses that Daniel’s body was actually found in the hotel but that Lucas dumped it so as not to get bad publicity.
SPOILERS: Who was the killer in the Sanatorium?
After talking to Ceclie, Elin realizes who the killer is. She rushes to the pool area where she finds Lucas, injured.
The killer is … CECILE. When Cecile was sixteen, Daniel raped her. Lucas knew and did nothing. The rape destroyed Cecile’s life. She became pregnant as a result. Terminating that pregnancy left her unable to have children.
Margot contacted Lucas and Cecile about her relatives who had been treated and abused at the clinic in the 1920s. Lucas buried the information as it would have been bad publicity for the resort.
Cecile then killed Adele because Adele helped Lucas cover up Daniel’s murder.
Cecile enlisted Margot’s help in murdering Laure. She killed Laure because Laure found out what Cecile was doing and threatened to expose her.
Cecile wanted to get caught for Daniel’s murder so she could “tell her story.”
Cecile and Lucas struggle and fall in the pool. Elin watches, terrified and thinking about the day her brother died. But she jumps in and saves Lucas. The police arrest Cecile and Lucas.
Do you think Cecile’s motivation for killing Laure and Adele made sense?
I can accept that Cecile waited years and years to get her revenge. She killed Daniel, who raped her. But then she killed Adele because Adele helped Lucas hide Daniel’s body, which meant that Cecile got away with murder. She wanted to get caught to get her story out.
Then she killed Laure, and then was going to kill Lucas, and I guess Elin would have been next? I don’t know – it was all a bit farfetched for me. Personally, I liked Margot as the killer a lot better. I guess she was helping Cecile, but still.
What WAS that final chapter of The Sanatorium? The Sanatorium Ending Explained (or not!)
In the epilogue of The Sanatorium, Elin and Will finally leave the hotel but as they board the funicular, someone follows them, someone who admits HE (or she?) was the one who pushed Elin into the plunge pool.

Was it Isaac, Elin’s brother, meaning he was the one who killed Sam?
Was it Hayler, the guy from Elin’s case back home? Is he now going to kill Elin? WTF?
Or was it someone else following her? (Be sure to check out the comments and decide if you are Team Isaac or Team Hayler or Team Someone Else. What do you think?
Yes! Elin is BACK in a sequel to The Sanatorium
So some of us in comments thought that, given that weird last chapter, there had to be a next book.
Good news: we may just find out who was following Elin.
Bad news: if you didn’t like Elin before (and there are a lot of people in comments who didn’t) she’s back in the next book.
Here’s the synopsis of The Retreat.
An eco-wellness retreat has opened on an island off the English coast, promising rest and relaxation—but the island itself, known locally as Reaper’s Rock, has a dark past. Once the playground of a serial killer, it’s rumored to be cursed.
Detective Elin Warner is called to the retreat when a young woman’s body is found on the rocks below the yoga pavilion in what seems to be a tragic fall. But the victim wasn’t a guest—she wasn’t meant to be on the island at all.
When a guest drowns in a diving incident the following day, Elin starts to suspect that there’s nothing accidental about these deaths. But why would someone target the guests, and who else is in danger? Elin must find the killer—before the island’s history starts to repeat itself.
Sounds familiar, right? Luxury resort with a dark past and Elin on the case! Elin does seem to find a lot of bodies in expensive wellness retreats.
Here is my Review of the Retreat and when you’ve read it (or if you don’t want to read it and just want ALL the spoilers) come over to my Spoiler Discussion for the Retreat!
Insights About Elin From Sarah Pearse
Also I recently listened to a podcast featuring Sarah Pearse, and I am here to say she seems LOVELY. I would love to have a cup of tea with her!
Here are some insights for those of you who aren’t fans of Elin (she didn’t bother me nearly as much as she did some of you lol. But I do get where you are coming from and so does Sarah!)
Sarah said she didn’t want the book to be a police procedural. She wanted Elin to be a “normal” person. (She is a police officer, but I she’s guess off-duty and out of her element in a different country.)
Sarah also seems aware that Elin is “somewhat controversial” and “perhaps a little intense” and I loved that she didn’t get defensive about it. A lot of authors would have been offended.
In the podcast, Sarah had some interesting thoughts about how female detectives in police procedurals get pigeonholed into a very masculine sort of characterization and wanted to try to work against that.
She also hinted that in book two Elin will have to reckon with her own memory and how reliable it is. IS ELIN SAM’S KILLER? Will she have to arrest herself? Anything seems possible!
Talk to me in comments! What were your thoughts about this one? That did you think about the ending of the sanatorium? I have seen varied opinions! And be sure subscribe to comment replies – you can subscribe to all comment replies or just to the replies on your individual comment.
Join the Spoiler Discussion for the Sanatorium!
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Hi: So glad you have written a review. I loved the characters and creepy vibe first half of this book. Second half, not so much. Why did Cecile mutilate her victims? Margot had worked with her, so why subject her to torture? Elin so frustrated me with her impulsiveness making bad decisions going it alone. I thought the ending might lead to a sequel. I don’t think it was Isaac. We didn’t explore the case she didn’t bring to closure. The ending did not come together for me. Was Lucas one of the original doctors? Far fetched. The visual depictions of the hotel were spot on and the cold and snow. Left with too many questions hanging. Will is a keeper, what he is doing with Elin is beyond me.
I completely agree – for me, this started out really promising and then slowly fell apart. Interesting idea that Elin’s case could have played some part. I don’t think Lucas would be old enough to be one of the doctors, but I agree that he could have had some connection to the sanatorium, like Margot did. Haha I agree about Will – he is a saint. And you don’t think that last mini-chapter suggests that Isaac was a murderer coming after Elin? I’m not sure what to make of it!
Agree, agree agree!
Thanks for this summary. I think it is definitely Issac at the end who plans to kill his sister. So it was he who was guilty all along of killing Sam. But that makes me rethink the other recent murders and how he could be involved in them…
But … why? (I don’t mean literally why but why end a book this way? I do not like it!)
The guy following them would be Hayler. There will be a second book…
Wow I did not know that. If you have a link to an article I’d love to read it!
Sorry. Just a guess on my side. Fully am behind your analysis.
Darn you sounded like you had some inside info. Well, the author has an upcoming book listed on Goodreads called The Refuge. It’s not listed as Elin #2 but maybe it is. Elin needs to decompress more after her stressful time at Le Sommet and has to check in to ANOTHER spa to recuperate and the killer follows her there and traps her in a sauna.
😀
Ben you sly guy. The second book was announced recently: The Retreat (did they change the title or did I get it wrong?) There was another book called The Retreat that came out this summer. Sounds like Elin 2.0, investigating crimes in a luxury retreat with a dark past.
I think it’s kind of unfortunate that they chose to pick yet another hotel type place for the book to take place!
I agree – just finished book two and it was VERY similar.
I just finished The Retreat, and Elin is already talking about going somewhere on vacation with Isaac. There will be a third, but I would never travel again if I was her..
Haha yes! I was surprised that the books were so similar, both with the travel themes and the general plot.
My spoiler discussion of the Retreat is here so feel free to come chat. Not that many people read The Retreat I think. I’m reading book three all by my lonesome.
Remind me who is Hayler??
Not sure if Ben is subscribed to comments. Hayler is the guy from Elin’s case back home. I guess it is somewhat plausible that he followed her on her trip, watched her the entire time, pushed her in the hot tub, and did all of this without her seeing him. Hayler or Isaac, it’s a weird ending unless Elin is in the author’s next book and her problems with Hayler and/or Isaac follow her. And quite a few readers didn’t like Elin at all so wondering if she’s going to be in the next book.
Ohhh I hope you’re right! Was there a book before that tells the Hayler story?
Hi, I just finished this book and honestly just felt like the ending was SO rushed and random. Just all of it. The bizarre history, Lucas and Cecile… the whole thing with the epilogue? I dont know. It just didn’t come together like I was hoping for.
The reason I didn’t think it was Isaac is because he stated that Elin was oblivious to him in the tram thing and also at the hotel….if it was her main focus of her previous case I don’t think she would be oblivious to him. I’m annoyed that it isn’t more clear!
I agree – these “surprise” epilogues that add an unresolved element seem to be a thing recently and I am not a fan!
Why would it be Isaac, when he referred to Will as Elin’s boyfriend?
Not sure what reeese’s connection with this author is or if it’s just that she’s a female writer ? This book was terrible. Made no sense. Never went into why Cecile dismembers these people and so much more … like was the bother the one who was watching them ? So ridiculous. Whatever. The small glass box with fingers. So stupid. I’m no author but I can’t believe I wasted my time reading this !
I felt the book was uneven. I thought the setting and the way the Sanatorium and its history were developed were really great. But the mystery aspect was … not great. I didn’t mind the main character (I read a lot of British mysteries so I thought she was kind of a typical British DI or DS) but a lot of people REALLY disliked her.
I read a lot of British novels as well and Elin is nothing like DiI or DS in the books I’ve read. I couldn’t stand her.
She was hard to like! Maybe the backstory with her case and her tragic past was supposed to make her more sympathetic, but for me it didn’t really work. If you have a chance, tell me some of your favorite fictional female British detectives!
I totally agree with you, waste of time. I didn’t finish it, couldn’t. I can’t believe Reese would recommend this. Very poor writing
There were so many typos, at one point, the author writes Celine instead of Cecile
I didn’t notice that!
I finally began laughing at the dialogue. I found the writing to be childish and over dramatic. All Elin did was sweat and have flash backs. Too many unanswered questions regarding some of the charters. The mini-chapter seemed very lame and almost a second thought by the author.
Haha you made me snort with the sweating comment. And yes, SO many unanswered questions.
I liked the book! I thought as messy as the ending was, the book up to that last part was really interesting and kept me interested. I liked the characters as well, I like a flawed hero and I thought Will, Isaac, and Laure added levels to Elin as well as being interesting in their own right and made for great red herrings. I was convinced at least one of them was in on it.
I was really confused by the epilogue. Couldve possibly been Isaac plotting against Elin but I got the impression it was the suspect from the case that gave Elin PTSD.
Gret idea, meh execution but I enjoyed it for the most part and am interested to see what else the author can do.
In a way I felt there were two different books in there. The idea of the remodeled Sanatorium and its dark history were one book. Then Elin and all her family drama was a completely unrelated (though interesting) thing. I didn’t feel like the two were woven together in a way that worked.
And you’re not the only one who thought the one following her wasn’t Isaac. Interesting!
I hated the ending but being a lover of this old building with a mysterious history trope, I sort of liked it. I didn’t understand Cecile’s motive behind the kill, what were the blood marks in laure and Issac’s room, whether Issac was a real liar or was it also Elin’s imagination..and to be honest, why was Laure following Elin around..or why did she run away like that before her wedding. She could have brought the police or could have told anybody else.
I completely agree with you. I love the spooky old Sanatorium trope, which is I think what sold the book to all of us. I also thought Cecile’s motives were confusing. I understand wanting to punish her rapist but the way she did it was odd. (I JUST read another book with a very similar revenge plot and will be doing a spoiler post on that in a few days.)
Finished the book today. Liked it, but mildly disappointed and somewhat confused. I understand Laure had the 2nd phone. But HOW did Cecile contact Elin with Laure’s phone (to meet in penthouse) before she killed Laure? Didn’t Cecile have to kill Laure first, then get the phone? The timeline doesn’t make sense with the text to Elin.
Interesting! I didn’t catch that. Maybe she just had access to it. Or it’s a mistake.
It would have made more sense that Laure actually contacted Elin to meet. Cecile with access to CCTV and hotel layout, would have known where Laure was hiding and could have intercepted her at penthouse. Unfortunately when Cecile was spilling the beans, James Bond villain style, she said she was the one who was using Laure’s 2nd phone to contact Elin–which is confusing.
That is true. Am I misremembering or was there some issue with the CCTV due to the storm? That would have been an easy way to explain that. And yes, I was not a fan of Cecile’s info-dump confession. I’m kind of a stickler for the honor system in thrillers that you have to leave clues for the reader, not just make up some motive out of thin air.
I believe it was Cecile who said the CCTV was down due to WiFi issues. My guess was that was a lie as she likely took it down once Elin started digging.
Thanks – I thought I remembered that correctly. I’ve returned my copy to the library!
Margot captured Laure and brought her down to the room. Cecile would have been able to take her phone whether she was alive or not.
For me – Laure was a smart woman- why would she hide in the hotel- participate in all this nonsense-
Why would she have the engagement party there in the first place with all the blackmailing. Vey unrealistic.
Laure wrote the actual message. But at the same time also reached out to Margot – they then arranged to meet BEFORE she met Elin. So I believe the actual text message was genuine.
Can you explain why Laure had the second phone? I have so many questions!
So many things wrong with the plot, and here is just one of them: Why did the UK PD want Elin back? She follows hunches instead of the evidence, doesn’t find the time to request backup in obviously dangerous situations, has taken nine months off on extended leave without giving the PD any idea of her plans, she’d possibly fail any psych tests given to police officers, let alone detectives….I can’t imagine why the PD would want her let alone promote her! There are so many better qualified people…Plus the local cops she liaises with by phone never seem to bother checking her creds with the UK PD. She could have been the killer playing with them!
And this is just a minor reason why the plot makes little sense. It gets worse in so many ways. Too bad. Maybe the movie will be better.
There’s a movie coming? The setting is cool, but unless they change a LOT I think it will have all the same issues. Weirdly I didn’t mind Elin as much as most people. I’m not sure why. I think it would have worked better to make her an amateur detective, or maybe just someone adjacent to law enforcement so it would be more plausible that she was in over her head.
I read somewhere (sorry, can’t dismember) that there will be a part 2 to this saga titled “The Office.” (A joke?) and that the two will be combined to create a film. Probably a couple of years away at least! Who would play Elin could make or break any film…
Thanks! Very interesting – do you think it would be set in England and centered around Elin and her case? And who would you like to play Elin??
I believe it’s the young man who found Daniel’s body and Lucas paid him to be quite.
Hi Jacqueline! Thanks for coming by to discuss! I thought a random skier found Daniel’s body (or at least that’s what my notes said.) Do you think that was Hayler?
It was a random skier named Jeremy, I believe…. But the old construction manager was the one that found Daniel’s body initially in the hotel room. He was the one whom Lucas paid off to keep quiet
Thanks so much!
I definitely think it was Hayler in the Epilogue.
I need to make a poll – I think Team Hayler might be winning…
How could it be Hayler? There were a limited number of guests at the hotel after the Avalanche, she would have recognised him?
I agree with that. Unless he were disguised or something?
It could not have been Hayler- there were a limited number of guests like you said-
plus, Elin interviewed all of them. So no way would she not recognize Hayler.
Good points – who do you think it was?
I don’t even care who it is.