Thank you to Netgalley and the publisher for the chance to read this early in exchange for an honest review.

I had no idea what to expect with this book going into it, I just knew that the premise sounded interesting. This is my first time reading a novel that uses this method of writing, but I LOVED it. This whole journey was amazing, and for any fellow gamers, this book gave me Subnautica vibes the whole time. This whole mystery slowly unraveling kept me wanting more, and I cannot wait for the next installment!

This was my first fully epistolary book and I loved the setup. It took a while to get used to the style and to place the different writers, but ultimately I enjoyed it! I loved E. and Henerey and their letters were by far my favorite - I would have happily read double the amount of their correspondence included. The premise of compiling correspondence was brilliant and I also grew to care a lot about E. and Henerey's siblings. I will say that the book is a little slow, especially in the beginning, but it overall felt necessary to understanding the world. This book really doesn't hold your hand with the worldbuilding, but I trusted the process and feel like I had a clear understanding by the end. I'm excited to read book 2!

I was very excited when I saw I was approved for this arc because I was intrigued by this premise. And I will read literally anything that involves the ocean in any way!
I thought this was a very unique book especially since the story was told through letters a form I had never read in a book before. Took a little longer than usually for me to read but I thought it was very enjoyable and something I have never read before!

I found this to be incredibly charming. The epistolary format worked very well for this novel and it is one that I generally enjoy very much. I am slightly disappointed to find that this is part of a series but I am excited for more from this world. Speaking of - the world building was lovely though vague. I don’t know if that was intentional or not but I would have liked to see more fleshing out of the actual world.

I received a free copy of this book from NetGalley and am voluntarily writing an honest review.

A Letter to the Luminous Deep is about two penpals who discover something amazing about their world. It follows their letters, and the letters written by those who came afterwards, trying to figure out what happened.

This book took me longer to read than any book I’ve read in months. Although I can usually read a third of a book in a sitting, easy, it was painful for me to read even 5-10% of this one. Why? Let me elaborate.

This book is written fully in letters. Although I’ve seen this done well before, this book does not do it well. There’s almost no tension in the book because the reader is so far distanced from the main actions. Literally huge parts of this book are letters written about other letters, so you’re getting this second or third hand, and it completely negates any excitement it might have had otherwise.

Secondly, this book is verbose and the writing is very flowery. I don’t mind a little of that here and there, but I got very tired of it in this book. It would have been nice once in a while if the author would have just told us what was actually going on because it was more than a little confusing.

Thirdly, even with the overwhelming amounts of exposition in this book, I had trouble understanding exactly what was going on. There’s so much stuff thrown at you, especially towards the end, that is not adequately explained. There’s apparently a sequel coming (which I won’t be reading) so hopefully at least that can be fixed.

Finally, the ‘cliffhanger’ ending. I put quotes around it because it is literally the most boring cliffhanger I have ever read. It’s more accurately just an end to the book that doesn’t wrap up, well, anything. The entire ending of the book is just as open and unsolved as the rest of it, which annoyed me to no end.

So, while I cannot in good conscience recommend this book, I do hope that there are those out there who enjoy it more than I did.

This story took me a little bit to get into, but once I was in... I was HOOKED. As a fantasy not revolving around fae or the other more "traditional" cast of characters in a fantasy novel I was unsure what to expect. Even more so, how would a fantasy take place in an underwater seascape without being all about mermaids and fish? Well... This story managed to create an engaging world that somehow felt both fantastical and relatable.

The narrative is told in a really unique way that progresses the story through a series of written letters, the equivalent of emails (automated post missives), and various "copies" of articles, journal entries, and the like. Telling the story in this way really gave the feel of a true conversation and archival mission vs. being told by a narrator perspective. These letters gave us an insight into the character's personalities, quirks, fears, and actual voices.

The focus of these letters and various writings all revolve around the budding friendship between E. who tends a little reclusive and a Scholar she admires, Henerey, and their subsequent disappearance. Told from the perspective of their respective siblings piecing together the mystery of what happened to them, the reader is granted a view into both the forming of the two's relationship as well as the siblings' response to learning more about their siblings. All the while, we are treated to discourse between the siblings of our two missing persons and learning more about their stories as well.

As with many a great story, this novel intertwines seemingly disparate events and has no shortage of surprises. As the first book in a series it sets up the future of the storyline well with a number of unique characters who all undergo strong character development without giving it all way in the beginning. I cannot wait to see how the second book compares and to hear more about E. and Henerey and their loved ones and acquaintances alike!

Straight up: I loved this book!

Now, it might not be everyone's jam, but the combination of epistolary narrative, a semi-spooky mystery, a very slow burn letter-based romance and a cleverly developed world made for a delightful reading experience. I will be honest that this is capital-S slow with Hawthornian-grade verbosity. The romance is heavily dependent on subtext (until about the 75% mark) and the author is very discrete in the clues that you, as the reader, are provided. Cathrall very closely toes the line between "an easily solvable mystery" and "actually, it is solved by someone with random info they never shared." I can't say the book had a twist (you do have all the data you need), but the mystery unfolded very organically and did keep you guessing and thinking until the very last page.

The item I loved the most, and what really sold the book for me, is the faith that Cathrall puts in her readers. As the outside viewer of these letters, you are just dropped into the thick of a strange world, with strange customs and lifestyles. The author however, doesn't spend time on tediously explaining everything and just trusts that the reader will use the context clues to put the story together. Since I hate very little more than chapters of exposition just to make sure the readers got what the author put down, this was very refreshing!

I can't wait for the next book in this series. I have so much I want to learn about this world and these lovingly developed characters!

Synopsis: A Letter to the Luminous Deep is a story told in the form of an epistolary, focusing on the letters sent between E. Cidnosin and Henerey Clel. The two begin sharing their interests with one another, until eventually planning to meet in person. Their feelings for one another blossom into a newfound romance and after discovering something unknown in the deep waters they both vanish from a seaquake that strikes E.’s home. Seemingly dead, their families are left to mourn them and wonder what caused this incident. That is until their respective siblings, Sophy and Vyerin, decide to team up and figure out what happened to them and why. But when Sophy and Vyerin begin to uncover more about what discoveries the two had made, as well as the love they had for each other, they learn that there is more to their lives than they had ever anticipated. Now Sophy and Vyerin must make a decision and hope that it will lead them in the right direction.

I must admit I had a hard time starting this book because I had not read an epistolary novel before but I got adjusted to it and even found a new love for the style! Following E. and Henerey’s journeys through their letters was fascinating to me although sometimes the pace was too slow for my liking. I really admired Sophy and Vyerins determination and growing friendship throughout the book. I absolutely loved the setting of this story, I have a deep love for underwater adventures, and this story was so unique!! While I do wish each individual character had more depth, I still liked reading each of their letters (and the differences between them). Henerey was such a gentleman to E. and I admired their relationship as it slowly grew from strangers, to friends, and eventually to more. The ending of the book I won’t spoil, but it definitely leaves me in anticipation of what’s coming next! I do recommend this series to anyone looking to read an epistolary with an underwater setting, mention of schools and scholars, a mystery to solve, bits of romance, and of course growing friendships!

Thanks to NetGalley and the publisher for this ARC!
Unfortunately this was a DNF for me. It is billed as cozy fantasy and I do generally like that. But I needed something more here that wasn’t present. The book felt so so so slow and there wasn’t that much world building to fill in that gap in plot pacing. The letter format was cool and didn’t detract from my reading.

Thank you to Orbit and Netgalley for the e-ARC. Where to begin with A Letter to the Luminous Deep? Overall, 3.5 stars. This book is written in letters which at first threw me off a bit, but it's so creative and mind-blowing. Two scholars, E and Clel share a love for marine life. They begin to correspond over an undersea mystery, but both vanish. A year later, their siblings, Sophy and Vyerin begin corresponding with one another trying to piece together the premise of their siblings disappearances. Letters stem between E and Clel from the year 1002, Sophy and Vyerin beginning in the year 1003 and other letters from side characters. Overall, this book is a "cozy fantasy", but a tad bit too long. I think if the pace was a bit faster, I would have fallen in love with this novel. With the way it ended, I'm not sure if I would continue onto the next.

This was marketed as Emily Wilde but underwater. Unfortunately, it does not live up to its inspiration. The novel feels clunky - the 2nd person point of view combined with epistolary makes you feel quite distant from the protagonist and it was difficult for me to care about any of these storylines. Couple that with the extremely poor world building and impersonal narration (overly formal language that feels overwrought rather than charming) and I am slightly shocked to have finished this.

This book focuses on the events leading up to the mysterious disappearance of E., an agoraphobic young woman, and her companion, Henerey, a scholar of classification. The story is told through letters between Sophy, E’s sister, and Vyerin, Henerey’s brother along with letters and excerpts of writing from E, Henerey, and others throughout. The book takes place in a world without land (except a small island that isn’t really discussed much). E lives in an underwater home known as the “Deep House”. One day she notices a “structure” in her underwater garden. She at first assumes it is the work of her brother, but later discovers the truth. She is entranced by the structure and after corresponding with Henerey for some time, he comes to explore it with her. At the same time, her sister, Sophy, is exploring a previously unvisited depth in the ocean with a group of scholars. The letters all follow a timeline to lead to the mysterious disappearance (and even shortly after).

The letter form was confusing at first, but once I got used to it, I found it a unique and lovely way to tell the story. You are able to see multiple points of view while hearing each character’s own voice in their writing. The world building is very well done. I enjoyed seeing E come out of her shell and the budding relationship between her and Henerey.

I did feel the book was very slow. I had a hard time pushing through it. I felt the most interesting aspects were in the last 10-15%. It ends rather abruptly. It is set up nicely for a sequel. Since it left off right as it got truly interesting, the second book should be faster paced and more interesting.

Overall, it’s really well written and unique. I’ve seen it compared to the Emily Wilde’s series. I wouldn’t go that far. It is far slower and the writing in general feels more formal. I do think it’s worth reading, and I will read the next in the series.

Firstly, I would like to express my gratitude to Netgalley, Orbit books, and Sylvie Cathrall for sending me this free eARC in exchange for an honest review.

Unfortunately, I had to DNF this book at 20%. I tried my best to complete this book, however I found that I had to force myself to pick this up. I believe this is partially due to my own lack of interest in this style of writing. This is classified as a Cozy fantasy (?) romance, which I thought I would enjoy. The general premise of the book is a series of letters written back and forth between different correspondences. While I initially believed this would be right up my alley, I found the poetic and flowery writing to be above my head and quite boring if I am honest.

Let me express that this is total personal preference and opinion; this was not an innately bad book, I just do not think I am the targeted reader. The world building is very minimal, which I can typically move past, however there was little to no educating to the reader on what is going on. This problem could possibly resolve after the first 20%, however I was unwilling to put more effort into this book at this time. I don't see myself picking this back up unfortunately.

This is the story of a wonderous world where most of the population lives either on or around the oceans. Somewhat like Waterworld (but way less depressing lol). The characters in this novel are mostly Scholars of various kinds. We follow E. and Henerey as they correspond with each other, first about a kind of long fish that E. sees out her window that Henerey can help classify, but then because they start to fall for each other. After a sea-quake at E.'s underwater residence, Henerey and E. mysteriously disappear. We also follow Vyerin and Sophy (Henerey and E.'s siblings) as they try and solve the mystery of where E. and Henerey disappeared to. 

I liked A Letter to the Luminous Deep, but not as much as I was hoping to. At first, I thought that the story being told in letters was an interesting idea, but as the story went on, there were times where I got a bit irritated at the limitations this introduced. For example, when Henerey and E. meet in real life for the first time, the only point of view we get of it is their letters about it, which leaves the event itself rather vague since the people corresponding obviously didn't need the event described to them since they were there. I wanted to see this meeting from someone's point of view in real time, because that's sort of what I expect in a romance. I expect to be there on the first date, so to speak. So, on the one hand if you like having that much room to imagine, you're going to love love love it. If you're more like me and (while I do have a healthy imagination) like it a lot better when mushy events are laid out with as many details as possible, you may like it less. Whichever way you like things though, this one may surprise you.

I really liked the prose though. Henerey and E. write lovely letters. Vyerin and Sophy write more casual friendly letters. Each person has a different personality that's apparent from the way they write, which I thought was a great way to build characters. I thought that the romance(s) were adorable, but the mystery of the 'Structure' outside of E.'s house got a lot more confusing as more was revealed. I have no idea if I can even picture in my head the events of the last few chapters because I thought they were confusing. I'm certain there were sketches of some of it, which helped, but apparently not as much as I needed. The pace was quite slow (as you can imagine given that this is a world where correspondence is still by pen and paper), which I did like at times but disliked at others.

So I'm kind of torn here. I wanted to like this one a lot more than I did, but I still definitely acknowledge that this method of storytelling had a few neat advantages, even if the disadvantages can be very apparent and annoying at times (at least they were to me). 

This book is going to be loved by a great many people, I think. Give it a try if it sounds interesting to you, because as I said, it might surprise you. I think that this particular one didn't get along with the way that my brain likes a story laid out. Like E., I have a Malady of the Mind, and mine can be really particular about things! 3.5/5 stars!

It should also be said that I think I might like this book a lot more in audio... Having the letters read aloud might be exactly what I needed here.

In Sylvie Cathrall’s enchanting tale, “A Letter to the Luminous Deep,” readers are transported to a fantastical world where underwater homes and vivid correspondence intertwine. Through sweet and heartwarming letters exchanged between the main characters, a captivating romance unfolds against the backdrop of a submerged civilization.

The book’s unique format seamlessly weaves together letters not only from the protagonists but also from their siblings, adding depth and mystery to the narrative. The smooth and dynamic writing style, reminiscent of beloved authors like Emily Wilde, makes it easy to immerse oneself in the story.

Set in a vividly rendered underwater world with a compelling mystery at its core, “A Letter to the Luminous Deep” offers readers a charming blend of romance, intrigue, and fantasy. With its captivating characters and immersive world-building, this book is sure to enchant readers of all ages. Special thanks to NetGalley for providing an ARC of this delightful tale.

Beautiful story, the writing was so captivating. My only complaint was the format- I had trouble following it.

thank you to netgalley for providing me with an arc!

This book was so beautifully written both in the correspondence to our main mystery couple who have disappeared, as well as the correspondence between their siblings desperate to piece together their love story and how they ended up vanishing. Cathrall did an incredible job in depicting a difficult relationship between siblings as well as E's struggle to fit in not only among her brother and sister but also in a world of academics. Henerey's private journal entries are what yearning is all about, he was so in love with her. The twist at the end with the sculpture was so well done and honestly i was surprised that it was truly something significant to the plot and not just something her brother had made and left. Overall i think this is a really strong book and even people who don't tend to read fantasy will enjoy reading this book and want more from the author.

A Letter to the Luminous Deep by Sylvie Cathrall is a cozy and mysterious underwater romance between two characters who have disappeared and follows their siblings who are trying to piece together the truth of what happened to them. Each letter between the characters reveals a little bit more about their world and the ocean planet they live on. Reading the letters between them made the book read with a more intimate feeling and it was certainly a unique way to write a novel. The world building in this book was extremely descriptive and the romance was sweet and heartwarming.

At first I struggled to get used to the way it is written as letters back and forth and to keep track of the timeline and characters, but that did become easier to follow after about the first third of the book.

I'd definitely recommend to anyone who enjoys underwater fantasies with aspects of romance and mystery! It will release on April 23, 2024!

Thank you to NetGalley, Orbit Books, and Sylvia Cathrall for the opportunity to read this ARC in exchange for a honest review!

Thank you to NetGalley and Orbit for this ARC in exchange for an honest review.

I found the synopsis of the story intriguing and was excited to delve into this one. I enjoyed the premise and found the idea of the letter exchange intriguing and the world building was beautiful.

Sadly, this one did not capture my attention until past the half way mark. I found the letters difficult to grasp on who was writing which as they were not easy to differentiate based on character personality. I found the back and forth too abrupt and possibly too much detail on the world building. I did like the inclusivity of the storyline.

Personally, this story wasn’t interesting enough for me but I do see how others may enjoy it.

Due out in April 2024, epistolary fantasy novel A Letter. to the Luminous Deep has, at its core, a very mysterious romance between two letter writers whose siblings are trying to discover the truth behind their disappearance. One protagonist is known only as E. (she hates her name), the resident of an undersea house who copes with a fantasy equivalent of OCD, who only just gets up the courage to write to a scholar she admires, Henery Clel, about a strange creature she saw swimming outside her window. Henery is entranced by her letter. He’s always been an admirer of the Deep House, where E. resides, and he finds in her a kindred spirit beyond the frustrating realm of academia. Readers learn about their friendship, and romance, through their letters, as well as through the letters and e-mail equivalent messages written by their siblings, who are both still mourning after the two disappeared.

While this is more of a fantasy than a traditional romance, and the way it unravels is not for readers who need a quick, straightforward narrative, part of the delight in the tale is unraveling things piece by piece. The world opens up a little more in each letter, as readers learn about this ocean planet with cultures based on prizing scholarship above all other virtues. Just as the world expands, the characters become deeper and more well-drawn with each letter. Sometimes their drafts are included, giving us greater insight into who they are, not just how they present themselves to others. E.’s compulsive behaviors, for which she does see a therapist (though not quite in those terms), shape her existence, but never make her a character that the narrative pities. She is who she is: brilliant and insecure, but passionate and loving to those she cares about. For readers who love second world, underwater fantasies, or epistolary novels, this is a lovely combination of both.