This book is just so cozy and there's just enough mystery to keep me hooked into what happens next! It’s written in epistolary form. So it’s perfect for people, like me, who are nosy and it reads pretty quickly! I love the way we are given snippets into different character interactions and watching different friendships form. The world building is surprisingly very vibrant and fleshed out, which is a huge accomplishment for a book written through letters and articles. I still really felt like I was in the Deep House in the coral reefs with E. and exploring the bottom of the ocean with Sophy. I really liked how the author was able to make me feel the emotions that the characters felt. Henerey and E are the absolute cutest and I need to know more! Sophy and her wife Niea are also a very cute match, as is Vyerin and his husband Reiv (they also have some very cute kids). I adored getting to know more about all of them, as well as the rest of Sophy's crew and her family. This book is one of my favorites of this year, hands down.

This is an epistolary novel, meaning that the story is told through letters, journal entries, articles, and other documents. It has a very academic feel, but also manages to be a story of love, friendship, grief, healing, conspiracy, and adventure. I really enjoyed it. It was so fun to watch the relationship between E. and Henerey slowly grow from professional to friendship to more. Sophy and Vy’s platonic friendship was also heartening to see, especially with the support of their respective spouses. I appreciated the way E.’s “malady of the mind” was depicted, especially through the various coping mechanisms she developed with the help Dr. Lyelle. As a nature lover, I was fascinated by the various forms of sea life described in the book. I loved that a few of E.’s sketches were included along with the text.

Note: This story is told in the form of letters that are trying to make sense of letters. It can get a little convoluted at times, but I enjoyed the overall story.

Additional Note: This is the first book in The Sunken Archive series. The next book has not yet been announced.

A Letter to the Luminous Deep was an intricate and alluring fantasy similar in style and intrigue to Emily Wilde's Encyclopaedia of Faeries and The Undertaking of Hart and Mercy.

Written from a magnitude of different points of view and timelines, we follow the story of how one correspondence of academic interest sparked the beginnings of a romantic love story and a puzzling mystery.

Any time the pen pal trope is incorporated into a narrative, I’m immediately sold. I thought this take on using two different sets of characters speaking through letters was really intriguing and unique. I loved seeing the two dynamics blossom and become interwoven into the story. The pacing and format of the story were a bit difficult for me to continually focus on, but I absolutely LOVED the underwater setting with a dash of academia—an amazing combo.

*Thank you to NetGalley and the publisher for sending me an eARC in exchange for an honest review.*

A R C R E V I E W 🫶🏼

📚 A Letter to the Luminous Deep
📝 Sylvie Cathrall 

𝚁𝙰𝚃𝙸𝙽𝙶: ⭐️⭐️⭐️⭐️ (4)
𝙶𝙴𝙽𝚁𝙴: Epistolary Fantasy 
𝚂𝙿𝙸𝙲𝙴: N/A

✨ This was an ARC gifted to me by Orbit Books via Netgalley. The following review is my own and contains my honest thoughts and opinions. ✨

𝙼𝚈 𝚃𝙷𝙾𝚄𝙶𝙷𝚃𝚂 💭
wow, what a delightfully whimsical and beautifully written novel! Comprised entirely of written correspondence between characters in both a present and past timeline, a brother and a sister of a missing couple work together to make sense of what happened. This may sound like a mystery - and while there are certainly mysterious elements to this tale, Cathrall has created a superb mix of cozy fantasy, underwater academia, good humor, clean romance and capped it off with a little cliffhanger. Here’s a breakdown of what I loved about this read and also a thing or two about why it didn’t make the 5-star cut (in my opinion).

𝙸 𝙻𝙾𝚅𝙴𝙳:

- Fun, smooth and witty writing
- Epistolary aspect
- Unique world & magic system
- Extremely likable characters
- Lovely imagery
𝙸 𝙳𝙸𝙳𝙽’𝚃 𝙻𝙾𝚅𝙴:
- Slightly slow placing

𝚁𝙴𝙰𝙳 𝙸𝙵 𝚈𝙾𝚄 𝙻𝙸𝙺𝙴 ⤵️
letter correspondence ✉️, unique magic ✨, underwater dwellings 🐙, witty writing 📝, whimsical fantasy 🌀, academia settings 📓, cozy mysteries 🤔

DNF at 10% because I simply could not make myself care. The voices for each character were too similar which made it impossible to tell who was writing and to whom in each letter and I kept having to flip back and it was simply too much work on a kindle for a cozy story.

Begging people to realize cozy stories should still have a plot.

Luminous Deep is told in the form of letter correspondences. It is a quirky, heartfelt blossoming romance book. I loved how each chapter or section were In the format of a letter. I thought it added personalized touches to this book. This book is truly inspiring, immersive and full of heart, it is a charming tale of epistolary about adventure within the depths of the magical seas. From the very first page I felt as if I was residing in the house underneath the sea as well. I felt I was along with E discovering new and fascinating creatures of the deep blue sea. Thank you to NetGalley and Orbit books for the chance to review this wonderful work of art.

Thank you to NetGalley and Orbit Books for this eARC!

A Letter to the Luminous Deep - Sylvie Cathrall

A year ago, Sophy lost her sister, E., in a seaquake, and Vyerin lost his brother Henerey. They start corresponding and sharing the letters that E. and Henerey were sending to each other to try and piece together the mystery of what happened. Sophy and Vyerin begin sending notes and journal entries, as well as letter they sent to their siblings, as the deep sea research mission that Sophy was on might be tied in to the mystery.

I truly believe you should go into this book knowing as little as possible. I love an epistolary novel, and the author did such a great job of keeping you engaged with the events of a year prior, but also invested in the platonic relationship that Sophy and Vyerin find as they are trying to heal from the loss of their siblings. The characters felt so real, even though you are reading their letters and notes instead of seeing them actually interact with the world. Seeing the mystery unravel was also done well, and I had no idea where it was going.

I got such The Guernsey Literary and Potato Peel Pie Society vibes, and I enjoyed every minute of this reading experience. If you want an epistolary novel set in a lightly fantasy/sci-fi setting, with heartwarming characters and intriguing mystery, then you need to pick this one up!

A letter to the Luminous Deep seamlessly blended academia, romance, and mystery all into one captivating book. Two siblings of scholars who go missing in an underwater mystery share their siblings letters to discover their mysterious disappearance.

I had some trouble getting use to the epistolary format of the book, but after a while, it was easy to fall in love with the characters and the mystery. I am a little saddened by the ending however, we get so close to solving the mystery and the BAM, book ends 😭 I really thought I was reading a stand-alone fantasy but I cannot express how much I need the next book ASAP!! 😩

Thank you so much to Sylvie Cathrall and NetGalley for providing an ARC in exchange for an honest review 💕

*Thank you to Orbit and NetGalley for an ARC in exchange for my honest review*

DNFed at 15%. When I heard it was epistolary, I didn't think it would be *entirely* letters. Moreover, there are so many recipients to track (each with complicated names). I did think that the setting was fun, but we didn't get to really explore it in what I read. It's just a little too academic for me, rather than the cozy fantasy I thought I'd be getting.

4.5 * Rounded Up

This was a delightful little book and I fell in love with these characters. They are all so kind and sweet, the way they care so deeply for each other and the way the author was able to convey all of that in just letters was remarkable. The story started off a bit slow but if you push through it you slowly start to piece this world together and it becomes more intriguing with each morsel of information you get in each letter. The sibling relationships were so well done, the setting was very cozy and the whole experience of reading it just left me with a smile and a need to have the next book immediately. This one does end on kind of a cliffhanger, and a lot of the main plot action happens at the very end of the book so be warned. I wonder what the next book in this series will look like, will it follow this same epistolary format or will it be something different. Highly recommend this one for a light academia cozy mystery!

Thanks to Netgalley and Orbit for granting me access in exchange for an honest review.

In this beautiful debut novel we follow the journey of E. who makes a startling discovery outside of her window in a house underwater. The discovery leads her to begin a to a correspondence with the scholar Henerey Clel. What starts out as mere curiosity and praise soon turns into mutual pinning, and the beginning of a beautiful relationship. Together they embark on a discovery that leads them to disappear in a huge seaquake.

A year later both their siblings begin their own correspondence trying to piece together what happened to them and what lead to the discovery. They pour through both E. and Henerey's letters, sketches, diary entries and notes to follow their footsteps and lead them to the same discovery their siblings made, and the hope that they may still be alive.

Tis was the most unique fantasy novel i have every read. It was entirely told in letters and correspondence but had so much emotion, world building, and plot. This was extraordinary and has left me baffled as to how the author accomplished a near impossible feat. The voices of all the characters were so clear, there was so much heart in every aspect of this novel. It was utterly beautiful and stunning and has become a top favourite novel of mine without a doubt.

I do think there is a target audience for this book and once it finds its target audience it is going to be deeply loved. However, I don't think I was the target audience, even though I desperately wanted to be.

This book is told completely in letter format. The parts that aren't letters (very few) are transcripts of the conversation, presumably taken by a present character. I think that is what made it difficult for me to love. However, the concept is wonderful and it was a beautiful story nonetheless. I would say this book is the definition of a cozy mystery/fantasy and the pacing is very slow.

Thank you to NetGalley for a copy in exchange for my review.

Love letters have got to be one of the most romantic things ever, so consider me hooked! I loved the whimsy and unique structure of this novel, as well as the charming banter between the characters. The underwater setting is like nothing I’ve read before (that I recall), and I was left wanting more.

From the moment I saw the cover of this book, I was entranced. With the further promise of an epistolary fantasy novel about solving a mystery and exploring a subterranean city I was all in..

Sophy and Vyerin are each mourning a lost sibling when they have the idea to compare the letters their siblings shared. Between all of these letters a larger mystery than any they could have predicted starts to unfurl.

I absolutely loved this. The characters are so fleshed out, and I adore the epistolary style. We get to know Sophy and Vyerin, and through their friendship we also get to know E and Henery’s romance. And every letter I read just made me want to know more and more about the world.

My only issue is that the main arc of the story feels unresolved, We’re left just as the team is coming together to investigate the mystery. It feels like I’ve got the first half of a truly lush novel. Other than the ending, this was an absolute joy to read and I anxiously am looking forward to the sequel,

Thank you to both NetGalley and Orbit Books for the opportunity to review this arc.

Thank you to Netgalley for providing me with an ARC of this story.
SPOILERS TO FOLLOW
DNF at 25%

This book seemed right up my alley. Mysterious deaths, love for your siblings, a fantastical ocean world, and it was written as a series of letters??? Sign me up!! Since it was also compared to Emily Wilde's Encyclopaedia of Faeries I thought it would be funny and heartfelt and while it does have that kind of air to it... this was also the most confusing array of letters I've ever had the displeasure of reading ever. What I like about epistolary stories is that authors are able to fit in a lot of characterization and world building in the letters that you write and if they don't I think generally people might have knowledge of the kind of world they've been transported into (i.e with Emily Wilde's I knew it was a sort of modern world with magical elements, or with Yours from the Tower (which I listened to as an audiobook and literally understood far better than this story) which was sent in the same kind of timeframe as the Bridgeton books are).

But this story and this worldbuilding was SO HARD TO FOLLOW. There were way too many moving pieces. I expected letters to be between Sophy and V and nobody else but as I kept reading there were articles that the characters sent to one another as well as letters from OTHER characters that infuriated me. (If you need to add articles from that world to bolster your world building I don't think you're doing a very good job explaining what's happening in that world from the characters own letters. I also don't think diary entires from a person DON'T HELP THE NARRATIVE.)

It was so distracting to suddenly be on the outside of E and Henery's story. I expected, when I first started, to only read Sophy and V's letters to each other as well as the letters E and Henery sent to each other AND THATS IT but then the author started to add in their older brothers, letters between the sister, letters from their sisters therapist, letters/diary entries from a different architect friend of their mom. So after failing to get very far after several days of struggling, I started to read other reviews of the story. There seemed to be a resounding comment that the story picks up at the last 25% of the book... but if I couldn't even make it halfway, I doubt I would have liked what the rest of the story holds for me.

DNF at 10%

I want to love this one so badly, but I’m finding it difficult to navigate (the book is written entirely in letters). The letters themselves are all written in the same stream of consciousness type voice, which makes them difficult to differentiate and the characters are all blending together. It has a very strong Emily Wilde’s vibe (I’ve enjoyed both EW books), but I’m 10% into A Letter to the Luminous Deep and barely anything has happened. I love the cover and the idea of this book, but sadly I’m going to press pause on it for now.

*I voluntarily read an advance review copy of this book*

Thank you to Sylvie Cathrall and NetGalley for the eARC copy of this book in exchange for an honest review.

Unfortunately, this was a DNF for me. I had so many high hopes for this book. The cover alone is stunning and sucked me in right away to learn more about this book - bravo to the designer and creative team! The premise of the book was also very intriguing. I adore books that are told in various multimedia styles and was excited to learn that this was all told via letters between characters. The idea that a love story could develop this way felt so cozy and comforting. Also, the idea of a mystery to solve the deaths of the first two characters felt as though it gave two major tropes in one book which I loved!

However, the writing style just wasn't for me. I felt that there were no differences between the character's voices and characteristics which made it incredibly difficult to become immersed in the story as I felt I was fighting my brain to remember who the letters were written between throughout the book. I would be tempted to listen to this as an audiobook at a later date to see if that helps with the characters being more defined in their personalities but as for now I sadly had to DNF this book.

I'm a huge fan of epistolary novels—they really hit the spot for me. There's something about the intimacy and authenticity of letters, texts, chats, and transcripts that draws me in every time. So, when I spotted a new one on NetGalley, you bet I jumped at the chance to read it.

Letters of the Luminous Deep is a captivating journey that unfolds through the exchange of letters, articles, and clippings, revealing the intertwined lives of two individuals connecting in grief through the letters of their siblings. While the transitions between correspondences may feel abrupt at times, it's a stark reminder of the fragmented nature of communication—after all, you can't always grasp everything from a single letter.

What I found particularly moving was the way Sophy and Vyerin found solace in each other's words and shared experiences, echoing the profound connection between Henerey and E in their own correspondence. The quirky character names did throw me off a bit, I found myself stumbling over them in my head, trying to get the pronunciation just right instead of being in the moment of the story.

Despite that, Letters of the Luminous Deep is undeniably a solid start at 3.5 stars and I expect it to be an enthralling series. I look forward to diving into the next installment and seeing where the journey takes us next!

lthough this was a bit on the slower side and the ending wasn't as conclusive as I would have liked, this was a lovely little epistolary novel.

It took me a bit to get oriented because the world-building was quite vast (and I'm not even sure I understood everything), but some of the imagery and ideas around a society so focused on the ocean were quite fascinating. The steady development of Henerey's and E's relationship and Vyerin's and Sophy's friendship was cute and fun.

The ending to this kind of felt like a letdown because it felt like all this build-up to just "wait and see in another book," so this might have been a solid 4 if more had happened. But overall, it was still an enjoyable read, and I'm very curious about what happens next!

Happy publication day to this absolutely beautiful novel!

I have to give the author credit for both a unique format to tell a story and the beautiful writing. Truly, I was so captivated by this book the entire time I was reading it. You get to watch multiple relationships develop and feel so connected to the characters. The author was able to distinguish the voice of every character in the novel, and that is rare to be able to do.

At first, I was unsure how the story would come together in the end as we were getting multiple different storylines, but I should have had faith because the author really did pull it together, and I am very excited to see what happens in the next book.

This is definitely a slower-moving story, so just a heads up for that as I personally, need to be in the headspace for a slower novel.

Thank you to the publisher and net-galley for an e-arc in exchange for my review.