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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Totally confused by the epilogue. Was it Isaac?
Hi Loti. There are main two opinions on this: Isaac and Hayler. If you read through all the comments you can see the arguments on each side.
I finished the novel last night and felt very irritated. I am grateful that you created this review. Because you know *knocks over teacup* I need to talk about this. First off, let me bore into Elin.
“Shady man stands in the darkened alleyway underneath a flickering light and takes a puff of his almost spent cigarette. The heat burns the tips of his fingers, but he likes the feeling. At least it’s something; he didn’t get what he wanted that shove into a pool didn’t end her. Elin is walking away with a guy who is way out of her league and will probably return to a job that she is utterly and completely underqualified for. “Maybe I will run and push her into a puddle, or smoosh her face in the snow … muahahaha that will show her. Or I will wait because there is time. So much time that I will leave this open-ended for no reason at all.” He cackles loudly. Then he coughs because smoking is stupid—the End.
So many questioned needlessly unanswered. 3/5 It was fun, but too many holes. Thanks for letting me rant ^_^.
I love your ranting; come back anytime. Excellent points. I wasn’t as much of an Elin hater as everyone else, but I can totally see why so many people found her annoying.
My favorite part of your rant: “What I’m still confused about here is that if Cecile’s goal was to expose Daniel as a rapist and destroy her brother’s reputation … why make it so convoluted? Everything pointed to Margot and her family’s heartbreaking history with the Sanitorium, but it wasn’t until Cecile had her “Evil-doer spills the frijoles” moment I couldn’t make the connection. I knew she was a part of it; I guessed when the writer described her strength and athleticism when they spoke about how much of an amazing swimmer she was, then suddenly she wasn’t. Passion like that doesn’t just go away. Something caused it. Then the CCTV deal. Pffft, Girrrrl is sketchy. I thought maybe it was a Flowers in the Attic situation, in love with her brother, jealous of any women who get’s near him. But rape? Pregnancy? Abortion? Infertility? Come on, throw us a frickin bone here! Did the pages of another novel get stuck in my book? Is this the story? What the actual … you get it.”
I agree 100% – that was the part that lost me. Her goal (expose Daniel, get revenge on her brother) didn’t match her actions at all. None of it made sense. It made more sense to have it be Margot.
Epilogue: WHY unless there’s a sequel and I think 99% of my commenters do NOT want any more Elin lolol.
I know this is an older post, but I’m glad to have found it! I truly want back the time I spent on this one! Like others, I liked the premise, and I found the first 1/2-2/3 or so to be very gripping and atmospheric, albeit repetitive. But as the storyline wore on it got sillier and sillier, and the ending was truly terrible. I thought it read like the author couldn’t figure out, “Who done it,” either, and just threw in the old rape story from out of left field. The epilogue was just bizarre-I absolutely don’t think we’re meant to think it was Isaac. Everything about the book suggested that Elin freezes up when she is in an emotional state, and that she misjudges people (Can we all agree she’s a pretty lousy detective)?? I didn’t have any sense of who the mystery figure was, but it was definitely a frustrating addendum.
No worries, Meg – the discussion is still active as not everyone read the book right away.
I completely agree that the premise and atmosphere was so promising, but the resolution was disappointing! I didn’t dislike Elin as much as everyone else did, but let’s just say I wasn’t that surprised that she messed up the case back home…
Ugh ok, just finished the book this afternoon and I have some THOUGHTS. Time to dump them on the internet!
Elin as a main character was both fascinating and frustrating. I liked her complexity but thought her family baggage damaged the main plot of the book. I wanted the author to pick a lane, either make it a family drama or stick to the hotel. I also agree with other posters who stated that she lacked the serious basics of detective work. Nancy Drew used more resources than Elin! (E-Lynn or E-leen??)
I also wished the author would have focused more on Margot if they were going to make her a main part of the story. We got two pages of her and then 50 chapters later BAM! All of a sudden she’s got this big investment and meaning in the story. I literally had to flip back to the beginning to figure out who the heck she was. And then (because things weren’t complicated enough) we have to introduce a second villain. Just….no. Tack on the assault, murders, family drama, relationship drama, weather, hotel history and I felt like the author was trying to get a blackout in literary bingo.
Last but most infuriating were the plot holes and epilogue! ARGH *shakes fist at the author’s book jacket photo*
Elin made it super duper clear that Laure pushed her into the plunge pool, then suddenly it was someone else? Unless Laure has a twin (real possibility at this point) I don’t see who else it could be. I feel like if Elin took account of everyone in the hotel and this person was there post avalanche, she would know if it was someone significant. Her dad? Definitely would have noticed, Hayler? Um yes, I think it would be shockingly clear if the person who tried to kill you was there. So who else, is Sam actually alive? Laure’s roommate who was pushed into glass, pressed charges, dropped them and then was never spoken about again?! I NEED TO KNOW, WHY CANT THIS BOOK HAS A CONSISTENT PLOT!
*sigh* Anyways, thanks for letting me vent and keep the theories comin’ !!
So many good points and I’m really happy you shared them. I was also frustrated by the family drama (which in the end didn’t have much bearing on the murders), the resolution (which didn’t make sense to me) and the epilogue (which really didn’t make sense.) I completely forgot about the roommate I will have to look that up!
Overall, I was not impressed with this book. I love the mystery thriller genre. I think that the descriptions of the scenery and people were good. However the actual plot seemed disjointed and very disconnected. It took me several attempts to actually get past the first 50 pages. Then the ending was very unsatisfactory. I don’t see why another character would be introduced then… this did not seem set up for a series. I don’t think it’s Isaac because of the reference to how she laughed and said something to “her boyfriend.” If it was Isaac, he’d be very familiar with Will and probably would not say just her boyfriend. Wouldn’t recommend.
I listened to the book rather than read it, and I’m wondering if that’s why I didn’t hate it as much as everybody else seems to have. Or maybe it’s because I can do other things while I’m listening to it so I don’t feel like it’s a waste of my time? I Truly think that some people thought they were plot holes because they were skimming it instead of reading it – especially if they didn’t enjoy it. I have been guilty of that with books.
For instance. the dismembered fingers were mentioned when they were going through the pictures of what happened in the 20s and 30s, so it was very consistent with other characteristics of the murdered bodies.
As far as the epilogue goes – I think there is a strong case to be made for Isaac – when he said he she was oblivious to him, it could be that he was following her and she didn’t notice. Also, who says that he hasn’t been watching her for a long time? Maybe he was secretly going back to see his mom and she didn’t even realize it.
Because I was reading everybody else’s comments from last year I just felt like I needed to chime in! 😀
Hi Amanda and thanks so much for joining the discussion. I always like to hear a different opinion. I did enjoy the book up until the ending. I didn’t think it made sense to have Cecile be the killer and thought there was way too much explaining necessary to have her motive made sense.
I think the Isaac theory is interesting though I don’t see why he’d need to follow her. (I’m also not a big fan of the new trend of epilogues that throw things back into disorder – I read mysteries because I like things being wrapped up!) But I’m sure the fact that there’s a second book is why the author did that and I’m definitely reading the next book to see who is following Elin.
I believed that Will was behind it because it seemed totally implausible otherwise to bear up with Elin 🤣
haha true!
The worst thing for me is that I have been to an old tuberculosis sanatorium in St Moritz and it was actually really beautiful. The big windows (for sun treatment) gave a beautiful view of the town and lake. I couldn’t quite reconcile the description of her sanatorium being scary and foreboding as a result.
Ooh, interesting. And in the book hadn’t the entire thing had been renovated, so I think it actually should have been beautiful. It would be different if it were an old abandoned sanatorium.
Im so glad that I was not the only one who thought the second half of this book was horrible! I felt the last half of the book felt rushed like the author just wanted to get it over with. This book needed way more back story development and had a lot of promise that completely fell flat. The whole plot was just rushed. This book is not something i would ever recommend! So disappointing!
I thought the book had a lot of promise but it really fell apart!
I listened to the audio and enjoyed it more than if I had read it I think. I think Sam didn’t die but was damaged and he was sent there? Too far fetched?
Haha Lisa – no theory is too far-fetched for me and that is actually a fun idea. I don’t remember the timeline of the sanatorium vs when Sam died. Does it fit?