Thank you NetGalley and Orbit Books!

An epistolary novel set in an undersea world of unknown origin-of course I was interested! It took me a wee bit to get into this novel, but once I figured out the rhythm and tone-and paid close attention to who was narrating each portion-I truly enjoyed the story, the characters, the world the author created, and the cliffhanger we are left on!

I have read very few epistolary novels that have done it well. This one did the job. It is set underwater in a magical acedemia setting. The whole premise of this book was unique and I truly adored it. I can see how it can throw readers off but truly i appreciated this format, it had suspense, romance, and executed characters so well. The world building was incredible. I have never read a story quite like this one.

Sigh. I was so ready for this fantasy to charm my pants off, but the voice of this novel made it so hard to keep going. I was unaware that this is an epistolary novel (my own fault) which I don’t typically go for but I have enjoyed some in the past. This one did not work out for me, and I think the reason is that all of the characters felt way too similar. It’s harder to characterize when they’re only communicating through one medium and I do think this novel struggled to separate characters from one another personality-wise. The actual sentences also felt dense and complex and were hard to process. Unfortunately, this just wasn’t for me. Thank you NetGalley and Orbit for the arc.

Thank you to Netgalley and the publisher for this eARC.

This book is a series of letters from multiple characters writing to each other. The plot sounded very intriguing to me and the cover is gorgeous.

However, I had a hard time following along with everything. The plot itself was slow, the letters were "scholarly" in the way they used certain words and was very formal, and the romance was lacking a bit for me.

Fitting to the title, "A Letter to the Luminous Deep" is a story told only in letters.

Sophy's sister ,E, and Vyerin's brother, Henerey, are missing (and presumed dead) after an explosion at Sophy's underwater childhood home. To help process her grief, Sophy begins to read through E's collection of letters from Henerey. Since he shares in her grief, Sophy reaches out to Vyerin to see if he has any interest in reading the letters from his late brother and if he has any letters from E to Henerey that he can share with her. Together the two berefet siblings learn the story of how E and Henerey's relationship developed as well as what REALLY happened to the couple - and it's not at all what they thought!

I had no idea when I started this book that it's made up entirely of collections of letters. There's no "normal" narrative here. In the beginning, it was a little hard to follow (especially with unusual character names and a very scholastic and formal tone of voice), but once I pushed through a bit, I really did get lost in the story. The whole idea of a story told in letters is unique and quirky, but also charming. I had no idea what to expect at any given point, but I was sucked into the mysteries of "the structure" and the civilization that created it. I look forward to the next book in the series.

It's all in letter form and the plot moved nicely. I did get lost in some of the plot and there was a lot of nothing going on but it was a nice, quick read !

Thank you Net Galley for giving me this advanced readers copy.
I did not finish this book. I truly believe this style of writing, epistolary (learned something new), is not for me. It is written as a series of letters between multiple people. While the writing was beautiful, I had a hard time keeping track of things. I truly wanted to love this book as in the beginning I loved the main characters and desperately wanted to get to know them. I've come to discover a new writing style and perhaps I'll come back to it one day.

I did not finish this book. I requested an advanced release copy because I was interested in the story's premise and captivated by the beautiful cover. I got through only a few chapters before I had to put it down. Reading this book was just...laborious. It's an exchange of letters between two scholars and then their family members after they go missing. The tone is meant to be between people who don't know one another very well but who are taking a chance to connect or work together. But because the characters are all highly intelligent and accomplished, the writing goes overboard in making these letters sound, at best "academic" and, at worst, stilted or meandering. I had no connection or interest in the mystery or any of the characters, even after four or five chapters. I would not recommend this book.

This book was a pleasant surprise as I had no expectations going into it! 3.5 Rating.

Told through various letters and methods of correspondence, A Letter to the Luminous Deep tells the story of two scholars who get to know each other while exploring a mystery from down under before mysteriously disappearing. A year later, their siblings come together to investigate their disappearance whilst fluttering through their correspondence for any clues and discover something life-changing.

This felt like an extremely cozy read, Cathrall Wields the language in a way appropriate for the time, though feels a little too formal at times, making it hard to get into. That being said, I do feel as though the atmosphere was well-detailed and painted a good picture. While I found that characters did not have distinct voices and kind of molded together, I found myself feeling rather connected to E. and Henery through their letters.

I do feel as though the pacing was a little too slow for my liking, with a lot of it feeling like filler and build-up, however, I do see myself picking up the sequel as I feel the need to see what happens next, and I do rather enjoy the author's writing style.

Thank you to NetGalley and Orbit Books for the advanced review copy in exchange for an honest review.

The ocean is my first love and I really wanted to love this book also, I’ll start by saying the cover is absolutely gorgeous. There were things about this that worked but the one thing that I didn’t enjoy was the author’s style or writing. I felt it very frustrating, too many exclamation points. And they were used at the wrong time too. I know that may seem trivial but it really took away from the novel as a whole for me. The story itself was ok. Pretty middle of the line reading.

I didn't know what to make of this one.

I was very skeptical after seeing the reviews for this one, but I tried to go in with an open mind. To put it plainly, this book was not for me. I sadly chose to DNF at the 20% mark. The premise of the writing style seemed super intriguing, but I didn't love the execution of it. It was very hard to read and even understand at times. It was also missing the romance element, which I am a romance girlie so I like a little romance over nothing. I just couldn't connect to this story or the nature of what was going on.

Overall, I do think this book has an audience out there, but it's a no for me.

I would like to thank NetGalley for the opportunity to read this ARC in exchange for my honest review. All thoughts and opinions are my own.

Rating: 3/5

3.25 stars rounded to 3!

plot: ★★★★★
A Letter to the Luminous Deep is told entirely through letters, and told in two separate times. one time, following Sophy and Vyerin (the siblings of E. and Henerey who have disappeared and are presumed dead) in the year 1003 as they try to make sense of the loss of their siblings and lean on each other for support. the other time, in the year 1002, mostly focuses on E. and Henerey corresponding to each other and slowly falling in love while also researching their water-based world around them. I should also mention that this story is set in a world predominately covered in water, so many people live on (or under) the ocean.

I loved the mystery aspect of the book, and I’m always a sucker for falling in love through letters. I also thought the world was really cool. for context, there used to be a society that lived in the sky, but there was an incident, “The Dive”, that caused the world to collapse into the watery planet below. the survivors of that incident created a new way of life on the planet, and that’s what brings us to the present. I would note that I wish we learned more about how the school system is set up and what that really means for how the world functions.

writing/prose: ★★☆☆☆
I won’t sugarcoat it - the writing was downright PAINFUL. it is written in a HEAVY academic language. extremely formal and detailed the entire way through. there were times where I was able to adjust to it and then settle in and get a lot of reading done, but it seemed like every time I took a break and tried to pick it back up again, I would struggle with getting back into the zone. however, the book was SUPER quotable. there were a lot of really sweet and pretty lines. (I have saved 39 quotes in my “favorite quotes” for this book).

pacing: ★★★☆☆
slow!!!!!!!!!!!!! I will say I think it feels slow just because of the writing/language. with the book being written in the format of letters, it actually reads quickly (if you can overcome the language).

humor: ★★★★☆ (3.5 rounded up)
I laughed a lot while reading this actually!! E. is really funny, and so are Sohpy and Vyerin when they interact together. I think my favorite bit of E. humor is when she refers to herself as the “Most-Deep-House-Oriented-Sibling”.

characters: ★★★★★
to be honest, right off the bat, without having even opened to page one, I can tell you that I hate the way Henerey is spelled. anyway, I love E. a lot. especially her take on dealing with her Brain not being kind to her and found her struggles with not being sociable and being full of anxiety almost constantly super relatable.

spice level: ☒
n/a—there’s not even a kiss (that we know of!)

illustrations and/or art style: ★★★★★
the only illustrations are from E. sharing sketches of things she observes in the ocean, but I loved them!!! I think they added to the story a LOT because it gave me a clearer mental picture of what she was witnessing.

audiobook narration: ☒
I read the hard copy of this book.

over-all enjoyment: ★★★☆☆ (3.25)
look, I really struggled at the beginning with this. I think I picked up the book like 100 times, before finally ACTUALLY starting it. it was not an easy read, but between the likeable characters, the incredible world, and the on-going mystery, I didn’t have any desire to stop reading! I am looking forward to the next one!!

I had to DNF this one 23% in. I just could not understand anything that was going on. Nothing was described to help understand everything. There were so many acronyms and names (people, places, etc) that made no sense to me.

Had to DNF this one. I might try and pick it up again soon. The writing was a little slow for me and I didn’t quite enjoy the way the book was set up. It just wasn’t for me personally!

I received an e-arc of A Letter to the Luminous Deep by Sylvie Cathrall from NetGalley in exchange for an honest review.
I was highly anticipating this and so excited when I was approved for an early copy. Penpals - like The Undertaking of Hart & Mercy? Big Emily Wilde vibes? I'm sold.
However, on reading I was extremely confused by the writing style.
I felt like I should know all the lore that was being dumped by the letters the characters were writing back and forth to each other - like clearly they know the world but I was lost completely.
I really want to like this so I might give it another chance when the audiobook is released.
DNF (for now) @ 11%

**I was provided an electronic ARC from the publisher through NetGalley.**

DNF @ 21%

This novel is first and foremost an epistolary novel. Lucky for me, I am fond of epistolaries, letters, diaries, journals of all sorts! Readers shall begin to make their acquaintance with the siblings Cidnosin (E.-rather suddenly gone missing, Arvist- perpetually self-interested, and Sophy- very much accounted for). In addition, readers shall encounter communique from the siblings Clel (Henerey-equally suddenly gone missing and presumably with E.- and Vyerin-also present and accounted for).

Sophy and Vyerin compile known letters between their respective siblings E. and Henerey as they try to determine what may have happened that led to their aforementioned disappearance. Their exchanged communications are interspersed with the letters their siblings wrote and with relevant excerpts of texts or public accounts of events.

The success of an epistolary novel (at least for me!) is in the voices of the characters being clear through each writing. I have letters from friends and have read historical letters between companions (for entertainment and for scholarly pursuits!); one can nearly always tell prior to the closing who is writing to whom in the exchange. This is the major let down for me of this novel- while there may be four or more sources of letters, there is one, solid, overarching voice that does not vary. I hope you might have noticed the (somewhat peculiar!) way I am writing this review. The parenthetical asides. The overabundance of exclamation points. The unnecessarily formal address broken up (rather unevenly, mind you) by wistfulness or playfulness. The entire book is written in this fashion. The plot moves at a snail's pace. Out of desperation, I looked at reviews only to learn that the "voice" issue remains throughout and that the plot does not begin to thicken until approximately 75%.

TLDR; this work was a mismatch for what I can tolerate for extended periods of time in prose. Wishing the author much success and hoping this book (with stunning cover art!) finds its audience. I confess; it was not me.

The world-building and atmosphere in this universe is *chef's kiss* Love the mysterious undersea vibes, whimsical creatures, building mystery. And the parallel stories between siblings are really sweet. Can't wait to see what happens next and I'll definitely be interested to read this one again.

The cover of A Letter to the Luminous Deep by Sylvie Cathrall, is absolutely stunning and the cover of a book always draws me in if done properly. So, winning there, and props to the illustrator.

The writing style with writing letters back and forth, I had hoped would only be for a few chapters at most of this book. Sadly, it was not. This back and forth really made reading this book (for me) a daunting task. I wanted more character engagement outside of letters. A positive of the book, the underworld exploration was fun but could have been colored more vividly with action and discovery.

I do want to thank NetGalley and Sylvie Cathrall allowing the early read and wish the book success to reads who may enjoy A Letter to the Luminous Deep.

Thank you to Sylvie Cathrall and Orbit for making this digital ARC freely available via NetGalley. My review is freely given.

I chose this ARC because so much of it appealed to me: the lovely cover, the idea of an underwater fantasy for adults, and the mysterious and romantic elements. I appreciate the representations of neurodivergence and mental/emotional turmoil. I like the sense of humor, particularly between E. and H. I was also grateful for the matter-of-fact inclusion of same-sex relationships.

The comparisons to the Emily Wilde series were a definite draw, but those books feel more traditionally told and also feature one POV. ALttLD, in contrast, is fully epistolary, with multiple letter writers who all sound the same (same humor, same Victorian vernacular, et cetera). That lack of variety made for a tiresome read. I think it would have benefitted so much from interspersing traditional storytelling between the letters. Instead, the author, several times includes pages of conversation that were purportedly written within a letter, but seemed contrived.

But I persevered and read the whole book. In the last letters, something is revealed that makes me realize that so much of this story depends on lack of communication. In fact, the 2 characters who struggled the most with social interactions were the most open and honest. Almost everyone else was lying and withholding information to a degree that infuriated me and prolonged the story in a way that did not feel organic.

The best parts of the story were the world itself. I wanted to know more about it, past and present. And the relationship between E. and H. was sweet and charming.

In the end, the unique world and story concept were interesting, but the pitfalls of a full epistolary format, the lack of variety of character voices and the heavy reliance on lack of communication did the story a disservice.

Such a great book. I love the setting, both under water and above. In my head it was a cross between Dinotopia and Sherlock Holmes. I loved imagining the outfits and machines described. The mystery that was slowly being unfurled was great. Sadly didn’t even realize that it had a sequel so expected more of a wrap up.