
Member Reviews

This book is one wild ride! It's an atmospheric, slow-burn journey that’ll keep you on the edge of your seat, even if you're not the biggest fan of horror. The story kicks off when Riccardo, a struggling writer, inherits his grandmother's villa in Milan after her mysterious death. Of course, he's hoping for some inspiration and maybe even a little cash, but when he gets to the villa, nothing is as it seems.
The house, once grand, has fallen into disrepair, and those butterflies in glass cases? They're not as charming as they sound. The more Riccardo digs into his grandmother's past, especially after discovering her diary, the more questions pop up. What really happened to her? And what’s up with the creepy vibe that’s creeping through the entire villa?
The pacing’s a little slow at times, but trust me, the last part of this book will leave you shook—that twist is one you won’t see coming. It’s eerie, it’s haunting, and it’s definitely not your average horror. If you're into stories that mess with your head and keep you questioning what's real, then you definitely need this on your TBR.
Big thanks to NetGalley for the ARC in exchange for my honest opinion!

This book is unreal!
For a majority of the book, it reads like historical fiction. With dual timelines, it is captivating and suspenseful. It keeps you wondering where it all leads. The final 20% or so is twisty and absolutely unreal. The final 5% slaps you in the face and is just WOW! I did not see that ending coming.
A very s l o w burn horror story indeed.
This is unlike any other horror novel I have ever read, and it's very good. I will never look at any butterfly the same way again.
I recommend everyone who enjoys a great gothic horror story to read Their Monstrous Hearts when it's available.

This was one of the creepiest books I've ever read! I truly could not read it fast enough- I've never needed to know what was going on more in my life. It's best to go in blind.

Twenty year old Riccardo is writing his first book, and things are not going well. He is struggling with writer’s block and stalling for time to get something to his agent, while unpaid bills are accumulating at a rapid rate. When a stranger shows up to inform Riccardo that his estranged grandmother has passed, and he has inherited her villa in Milan, he thinks it might just be the opportunity he needs to bounce back financially and find the inspiration he desperately needs for writing his book. Riccardo soon finds that things seem strange at the villa and he discovers a manuscript written by his grandmother, which he hopes will give him answers to her death. As Riccardo delves into Perihan’s manuscript, a haunting horror begins to unfold, and he must decide if Perihan’s story is fact or fiction, in order to survive.
Their Monstrous Hearts ended up being a read in one day book for me, because I couldn’t put it down without knowing how the story ended. The book is told from Riccardo and Perihan’s POVs, with most of Perihan’s part of the story told as flashbacks. I was definitely interested in Riccardo as a character, with his struggling writer persona and estrangement from his family, but Perihan is definitely the dominant character. We see her struggles as the youngest in a family full of daughters in Turkey, and the drive that develops during her younger years, that motivates her character throughout the rest of story.
The pacing of the book is on the slower side, as most of it focuses on Riccardo reading Perihan’s manuscript. There are some horror elements interspersed throughout the first part of the book, but the majority of the horror exists in the last 30%. As a TRIGGER WARNING, there are graphic scenes depicted of child death in Chapter 21. I did feel like this part of the story didn’t fit in, and could have definitely been left out without affecting the rest of the book.
I really enjoyed the butterfly imagery, and how insects can be beautiful and terrifying at the same time. And Turhan does an excellent job of addressing the true monster/monsters in the story. I was very surprised by the ending, because it delivered a great horror twist, that I did not expect. It was definitely worth the slow burn horror build up!
If you love dual POVs, unexpected villains, shady side characters, and surprising horror twists, then I would definitely recommend Turhan’s first English language debut novel.

The dual timeline is still a relatively interesting approach, and overall the story was well-paced, but at times, it felt bloated, like a student using a thesaurus to pad the word count so they didn’t get marked down on an assignment. The synopsis of a struggling young writer being surprised by the gift of a dead grandmother’s gothic estate (not to mention the gorgeous presentation of the novel itself) set high expectations for me, but unfortunately the writing didn’t live up to them. 1.5 rounding to 2 stars

I liked the dual timelines and the cover! The author is talented, but the story was too slow for my taste. I need more action I think to keep me interested for the long haul.

I was interested in this setting, story, and characters, but the writing was incredibly amateur in my opinion. It was flat and uninteresting.

First off, the cover of this book is absolutely stunning! It’s giving creepy gothic vibes which I absolutely love! It brings out a lot of character in a book and is what drawn me to it.
Thank you to The hive and @harlequin books, htp books for gifting me this copy! I truly appreciate it and will definitely be reading more from this author in the future.
Who would have thought an author would make butterflies sound creepy! Literally gave me goosebumps as I was reading and that’s how you know the author done something right writing this book 🙌🏼🦋
This story takes place in Milan (which I love btw) and you have your MMC Riccardo where he is inspiring to become a writer but is struggling with it and he receives strange news that his grandmother passed away and finds out he inherits her villa in Milan. He hasn’t been back to her villa in a long time and remembers it being luxuriant especially the butterflies in the glass cases. Perihan his grandmother was obsessed with butterflies.
He then discovers a manuscript while he is at her villa that is labeled to him and reads it. The manuscript unravels some mystery and secrets to his grandmothers creepy butterfly collection that identifies some dark spots of eternal life and magic of monsters. It leads him down a path unexpectedly and starts to experience weird things in the house. With his journey reading more into the manuscript, he learns more about these butterflies where you can desire to extend your life for eternity. You die and come back to life and a butterfly will come and find you to resume your life. I found this part in the book interesting especially reading about the teardrops with the conversation with Fumito.
This is great for those who are into gothic/horror. The writing felt a bit repetitive but was still overall great and felt a bit slow for me at first but it definitely picked up and kept you on your toes waiting for that next twist to happen!

With writing that is both dark and vibrant, this is definitely an author to watch! I loved the layer upon layer of mystery.
Inheriting an old house is a trope I fall for every time, especially when there is a creepy factor. We also get this really ominous butterfly collection that I found incredibly intriguing. But, it is the diary belonging to the woman who owned the house, our protagonist’s grandmother that I really vibed with!!!
I highly recommend this one!

I really tried to enjoy this book, the premise and cover really drew me in. I struggled my way through it for weeks on and off because I couldn’t immerse myself in the book. The writing style wasn’t really my cup of tea and at times felt like I was reading something written by a robot.

I loved the beautiful cover for Their Monstrous Hearts and it sounded like an intriguing premise, so I was excited to request and read it!
When Riccardo learns he has inherited his grandmother’s mansion and butterfly collection, he hurries over to Milan. However, when a mysterious diary appears and his grandmother’s friends seem to be holding secrets, he starts to wonder what legacy he has inherited.
Their Monstrous Hearts uses a narrative technique that I’ve seen used quite a lot in my 2025 reading – present day narrative interspliced with diary entries from the past. Riccardo is reading the diary in the present day which tells the story of his grandmother’s life and her adventures with the butterflies. This technique fell a little flat for me, as most of the present-day text is rendered obsolete if Riccardo had just read the diary a little faster and in one sitting. I also found that the chapters alternated without any real signposting that you were now in the diary entry – having them in italics or including chapter headings would have really helped with this.
I loved the premise of the book - without giving too much away the butterfly aspect and what people would do to hold on to the power was unusual and interesting. I really enjoyed the ending, and this really saved the book for me. However, I found the writing in the middle quite repetitive and slow. I didn’t really feel any proper stakes or tension in the present-day text and the flashbacks took too long establishing character rather than moving the story along. Speaking of characters, I also feel that we didn’t get to know Riccardo as much as I would have liked and so I didn’t feel particularly invested in his story.
Overall, Their Monstrous Hearts is an unusual and interesting premise, but it’s writing style sadly let it down. Thank you to NetGalley & Harlequin – Mira for the chance to read the ARC in exchange for an honest review.

When a stranger brings news of Riccardo's grandmother dying, Riccardo discovers that he is now the inheritor of her Milan villa filled with her collection of butterflies. Riccardo, who is a struggling writer, chooses to go to her villa where he finds his grandmother’s diary.
The more Riccardo reads from the diary, the more questions he ends up with. While hoping for inspiration on his book, he also dives into exploring his grandmother’s death.
This book had the makings of a great story. I loved the premise, the atmosphere, and the setting. I always love books set in Italy. I also appreciated the uniqueness to incorporate these butterflies into the horror. Unfortunately, I felt that the writing and structure fell short for me. I found myself a bit confused in the middle of this story and the writing wasn’t the most advanced. The beginning and end were the strongest parts of the story, but I got a bit lost in the middle and it was hard for me to keep interested in this book at times.
I read somewhere that this is the author’s first book written in English which makes me less concerned with the writing because I know that this is miles ahead of anything that I would be able to write. I think with some more practice, this author can really polish off the bumps in prose. For being his first English novel, I’m actually pretty impressed. I’ll definitely read more books by him in the future.
Thank you to NetGalley and the publisher for the arc. All opinions are my own.
TW: suicide, child death, gore, violence, animal death, injury detail, blood, body horror

4/5 Stars
This book was not what I expected, but that wasn’t a bad thing. It starts slow—almost too slow—but the gothic atmosphere and creeping unease kept me hooked. Riccardo’s inheritance is less of a gift and more of a mystery wrapped in dust and butterfly wings. Perihan’s diary added depth, though it didn’t always feel like a real diary. The ending? It wrecked me. Not sure I liked it, but I get why it had to happen. A haunting, weird read that lingers.

The storyline for this book was great. This author managed to make butterflies creepy! Our main character is queer, so bonus points from me.
The writing isn't amazing but this is the author's first novel in English so I'm not taking points off for that. The ending was so abrupt that I had to reread the last two chapters to ensure I didn't glaze over any details.
I received a digital copy and later an audio copy of this book. For once I am not going to recommend the audio. The male narrator's narration voice was lovely. His character voices however were so similar it made it hard to differentiate which character was talking. The female narrator's voice was so soft it could have put me to sleep.

Thank you HTP and MIRA for this ARC and ALC.
When I was a child, my teacher read our class an old indigenous tale about the friendship and turmoil between the Pine trees and the Maple trees. The Pine tree boasted about not losing its needle through the winter, and the Maple was saddened by this. But during the winter, a small sparrow took shelter and solace in the density of the Pine, and in the spring, it built a nest in the Maple. There is a time and a purpose for every thing and for every need.
Needless to say, over 30 years later, this story has stuck with me. And so, too, will Their Monstrous Hearts. The symbolism is the same, there is a cycle. There is no life without death. Death without life. The comfort I felt reading the words in this book was akin to listening to my teacher relay that story. It made me feel rooted and connected. And it made me feel joy and a prick of fear. Because we humans really do take matters into their own hands against Mother Nature, don’t we?
This book was so richly written that my teeth ached, in the best way. Like when you get the perfect fork full of the Matilda chocolate cake. It was delectable. I loved the narrator, loved the way the language rolled off her tongue. The way she told the story - and the storytelling itself - was so wonderfully old school. I felt like I was sitting around receiving the gift of history and heritage in the form of a story told around a fire.

This books was a real slog. I got to about the 50% mark before finally giving up. I just didn’t find the story suspenseful or atmospheric in the slightest. I think this was partly due to the way the story was presented. The book goes back and forth between our main character Riccardo and his grandmother Perihan’s manuscript. I feel like this worked, but we would periodically get scenes from Perihan’s friends perspectives and it would cut all the tension. I would be sitting there reading Ricardo’s section thinking “what’s up with all these people at Perihan’s house? What are they doing here? What is their motive?” And then the next paragraph would be the friends having a conversation out of earshot from Riccardo outlining all their plans and motivations. I feel like this happens in a lot of books, but it’s that not knowing that builds tension and that wasn’t the case in this book. I also thought there was going to be a lot more desperation from Riccardo, but he seems to be fine just lounging around reading Perihan’s manuscript. Maybe he starts to grow desperate later, but if it hasn’t started at the 50% mark, I can’t imagine it would feel properly developed.
I also wanted to make a quick note about the writing style. It isn’t great. I read another review saying that English is not the author’s first language and this is their first English written novel. While I think it’s amazing they were able to write in a non-native language, that doesn’t mean the writing is “good,” it just felt juvenile and repetitive.

This book was and is beautiful the use of the atmosphere as well as just the hope the MC has with what is given to him really shines off the pages. I will say this isnt an exclusive horror novel its so much more than that. It will make you think about your own decisions and the what ifs in your life. I loved the butterflies it just all came together beautifully.

This book was not for me, but will definitely appeal to fans who enjoy a good psychological horror story. Reading this book gave me chills and I think the story will stay with me for a while. I enjoyed the author incorporating some Turkish culture into the story and found it overall to be a suspenseful read. It just ended up being a lot more creepy than I expected and I also did not enjoy some of the body horror included.

Their Monstrous Hearts by Yiğit Turhan is a haunting and atmospheric novel that combines dark romance with chilling supernatural elements. Set in a world where monstrous beings and humans coexist in an uneasy balance, the story follows the tangled emotions and dangerous desires between the protagonists. The central characters are complex and flawed, with their growing connection both beautiful and unsettling.
Turhan masterfully creates a moody, immersive atmosphere, with vivid descriptions that pull you deep into this eerie world. The book delves into themes of love, obsession, and the monstrous nature of its characters, exploring how far one will go for the sake of love—and what makes a monster in the first place. The pacing is compelling, with enough twists and tension to keep readers on edge.
While some elements of the plot can be predictable, the emotional depth and dark allure of the story make it a captivating read for fans of Gothic romance and supernatural fiction. Their Monstrous Hearts is a mesmerizing tale of love and monsters, with a twist that lingers long after the final page.

Ricardo has few options. No money, too many bills, and a severe case of writer’s block. He learns that his grandmother, Perihan, who he has not seen in many years has died, and he travels to her home in Milan for the funeral.
Her once grand house is vastly different and the people who are there seem to have their own agenda. When he finds Perihan’s diary, he is not sure if he is reading fact or fiction. Whatever it is though, it tells a very disturbing story.
Told by Ricardo in the present and through diary entries explaining his grandmother’s past, the more that he learns, the stranger the story became. Is it fact, fiction, or a combination of both? Butterflies play a large part in the story and by the end……. Well, I cannot say more because of spoilers. Let me just say I was shocked at how the story ended. I was screaming “No” at my Kindle, though I do understand why it ended this way. I may not have liked what happened, but I did enjoy this book, the first one I have read by this author.