DNF @ 21% - I found the letter format to be a little confusing and I kept getting characters mixed up. Unfortunately, the writing style just didn’t fit what I look for in a fantasy novel.

I was so intrigued by the synopsis of this book and wanted very much to enjoy it... but it ended up falling short of my expectations. The underwater world building was disappointing, the slow pace and lack of a plot made it a snooze fest, and the characters were not as interesting as I had hoped.

Thank you to NetGalley and Orbit Books for providing me a digital reviewer copy in exchange for my honest thoughts.

Not for me. I could not get interested in this book. I attempted several times to read it, but to no avail

I DNF-ed at 30% into the book. I really wanted to enjoy this book but it just wasn't for me...
I think that if you like cozy fantasy that is more character focus rather than plot focused you would like this book! I think I am just learning that I am not a cozy fantasy girl, I need some sort of plot of higher stakes to keep my attention and interest. The book hints at this big mysterious disappearance but without really discussing it much (I am assuming it will be discussed more later) but I just didn't feel very invested in this mystery. I liked that the book was written as letters or correspondence from one character to another it is unique literary style that I enjoy. It is more complex especially since these letters took place across several years but I enjoyed this writing style. Our main character E has a lot of anxiety and reading this at a very high stress/anxiety riddled time for me was a lot to handle. I do think that this book is well written and that it has an audience. I just unfortunately am not that audience.
Thank you so much for allowing me the chance to read this book though! I hope it continues to find success within the cozy fantasy genre and audience. I apologize for the delayed review due to graduate school.

I feel like this could have been interesting if you’re really into fantasy, but personally it just wasn’t for me and I didn’t love it.

✨5 stars!!✨

Thank you Netgalley and Orbit for this eARC!!

I've never read a book like this book, both in style and in theme. I absolutely loved watching these two people fall in love through their letters. I can't wait to read book 2 because of that cliffhanger at the end.

This is a wonderful cozy fantasy/cozy mystery book that absolutely blew me away. I am not always the biggest fan of cozy fantasy but I absolutely want more of this! I cannot wait to read the sequel!

I have tried to read this for several months. I have started and stopped so many times. I love the premise, and epistolary novels are one of my favorite narrative structures, but I don't get on with the writing. Also, each POV sounds the same. It is hard to distinguish them, and it is frustrating.

Thank you to NetGalley and Orbit for a gifted copy in exchange for an honest review.

A solid and beautifully written debut.
I am always a fan of books told through journals and letters, and this was a joy to read. I accompanied my reading with the audiobook and I would highly recommend that experience to other readers as well, the narrators are wonderful and truly help bring the story to life. I’m excited to continue this story in the next book of this series

This was such a fun book! It’s an epistolary novel (which I love), so it was just perfect! I read the physical and listened at the same time (highly recommend- the audiobook is a full cast) and was entranced.

I won’t lie, it took me a second to get into cause I could not figure out what was going on. But once I got into it, I was INTO it!

This had me smiling like a fool (a happy one!) and I couldn’t put it down!

I really enjoyed Sylvie Cathrall’s writing style—her prose is thoughtful and evocative, creating a vivid atmosphere throughout the book. However, despite giving the epistolary format a sincere effort (even attempting the story twice), I found it difficult to fully connect with the narrative style. Ultimately, I was unable to finish the book, as the letter-based storytelling didn’t quite resonate with me.

A Letter to the Luminous Deep was a really good debut novel. I couldn't wait to read a book that has a romance set under the sea. I loved how it was written through letters. Some parts were maybe a bit slow. Overall I believe the world building was very very good. Thank you netgalley for an arc.

This was one of the most unique books I’ve read this year—told entirely through letters, journal entries, and other documents, it weaves a quiet, romantic mystery at the bottom of the ocean. It’s tender, lyrical, and filled with wonder. The romance (between two researchers who’ve never met) unfolds so delicately, and the speculative world—full of bioluminescent creatures and strange underwater science—is a joy to explore. It’s not fast-paced, but it’s emotionally immersive and beautifully crafted. If you liked The Long Way to a Small, Angry Planet or The Deep, this is one to savor.

A beautifully written and unique book, I found this to be really interesting to read, though I think the formatting of my copy was a little odd. I plan to buy a physical copy of this book to re-read now that it is published. See below for my updated review!

Plot- or character-driven? Character
Strong character development? N/A
Loveable characters? Yes
Diverse cast of characters? Yes
Flaws of characters a main focus? N/A
I LOVED this book. This book deserves to be savoured and the relationship building is a slow-burn romance readers delight. I especially loved the way that the author built the plot and left things out when they weren't in letter format. For an epistilory novel, I really was never very sure what was going to happen, even though I could guess. I can't wait to read the second book in this duology and see how everything comes together!

A stunningly imaginative epistolary fantasy that unfolds through letters and scientific journal entries, uncovering a deep-sea mystery and a blossoming romance. Cathrall blends speculative wonder with emotional tenderness. For readers who love cozy fantasy with big ideas. Gorgeous!!

I think it would be easy to give up on this one too early so mood readers might have a tough time giving this a proper chance. It took a bit to get the voices straight for me, but once I did I really enjoyed. It paid off but I’m wondering if there is a way to better hook the audience earlier!

I struggle with epistolary format unfortunately. I had the same problem with This is How You Lose the Time War. So there was always going to be a limit to how much I liked this book. If you like an epistolary format, I think there’s a lot you’ll really like here.

This book was so much fun! I am such a sucker for letter writing and to have a whole book of it is just wonderful. The characters felt so real and at times I almost felt guilty for reading their personal thoughts. My favorite aspect of this book however was the setting! Thats one thing that can sometimes be overlooked in letter writing stories but the imagery in this book was breathtaking.

My favorite part were the characters. I enjoyed the interactions between the siblings especially. There were some heartbreaking moments that got me a bit emotional. The letter format really lends itself to this buildup and is something that I rarely see.

The nature and technology of this world was also very interesting. I would like to note that I listened to the audiobook and the cast is phenomenal.

I will say that the pacing got pretty slow in the middle and then picks up again. The last quarter felt rushed.

Overall, I would recommend this to readers who are character driven and like good mysteries.

That was a VERY slow burn plot. It took me a while to read this. I'm not sure if it was the way it was written through letters and correspondence, the old English feeling of the way it was written, or just how dragging and slowly the plot progressed. I rather liked the slow romance development by penpals between E and Henry, and the friendship between Sophy and Vyerin. Once I finally got to about the 65/70% point I could NOT put it down. The ending leaned a lot more sci-fi than I was expecting which was interesting and leaves me excited and interested in the sequel.