Thank you to Netgalley and the publishers for this advanced reader's copy and the opportunity to read this early. Review has been posted on Waterstones and Amazon.

A great light academia read that’s unique and fun! I really enjoyed the mystery aspect to the story and found it engaging!

I cannot stop thinking about this book. So far, my favourite book of the year. The mystery still haunts me and I cannot wait to read the conclusion. The world came alive under the masterfully written letters which proves the genius of the author!

Thank you for the arc. I love academia books and this light academia had me hooked too with the letter-type storytelling. I love a good slow burn and i adored the setting of this book.

This is one of those books I actually had to think long and hard about after finishing it because I was so conflicted over how to rate it, since there quite a few things I enjoyed but also at least as many I was frustrated with.

Starting with the positives, I was immediately hooked on the premise for this book: a light academia epistolary underwater fantasy mystery romance sounds like a mouthful, but also exactly like the type of book I would enjoy. Told entirely through letters, the book revolves around the disappearance of reclusive E. and scholar Henerey Clel following a mysterious discovery they made, and their siblings' attempts at making sense of this.

The relationships that develop between the different characters, which readers can witness slowly unfurling through their correspondence, were by far my favourite part of the book. Interactions between the different characters are realistic and rich, whether that's the sisterly relationship between E. and her Sophy, the budding romance between Henerey and E., or the friendship between Sophy and Henerey's brother Vyerin, bound together by grief and the need for closure. It is hard to convey such deep levels of human connections only through letters, but the author did a wonderful job of it.

The world is also intriguing and lavishly built, with many natural wonders and sea creatures being thoroughly presented throughout the book as the different characters engage in their research, and I was keen to learn as much as possible about them. What comes across as less clear in the world building is the way society is structured and functions, despite references to academia and its structure throughout. Now, it is entirely possible that this will become clearer in the next book (or books?) in the series, since this is only the first one - something which I realised very late on, as for some reason I was convinced I was reading a standalone.

What I struggled most with in reading this book were the writing style and the pacing. As the characters are all scholars or researchers, their use of language reflects this, with a prose reminiscent of Victorian English laced with academic jargon. This isn't typically an issue for me, since I'm used to reading academic papers for work, and I enjoyed other books written in a similar style: for instance, Emily Wilde's Encyclopaedia of Faeries is narrated through research journal entries and I had a great time with it. With A Letter to the Luminous Deep though, the sparks just didn't fly, and I ended up finding the style verbose and overly weighed down by unnecessary formalities, even in letters between siblings.

I was also completely unable to distinguish between the different voices, as all the characters sounded exactly the same in their writings. At one point, I had to switch to the audiobook version (which is excellent, by the way), as the production featuring multiple narrators finally allowed me to understand whose letter I was reading without constantly having to go back to check. This made me feel as though the book was just dragging along, something which wasn't helped by the extremely slow pace. Now, I generally prefer character development to plot so maybe this was a case of me reading this book at the wrong time, but I really struggled to get through it for large sections in which it felt as though nothing at all was happening. And then, everything happened all at once, ending on a pretty huge cliffhanger, which I found pretty frustrating.

I think I'll probably pick up the next book in the series since I am somewhat curious as to where the story might go next. This is also a debut and I see some great potential for the author in the next books, especially given how the relationships in this book were some of the best written I have come across recently. I also liked the queer normative society and the mental health rep (with depictions of OCD and anxiety), so there's definitely a lot to save here!

I’m officially hooked on this light academic romance set in a magical, underwater world! Told entirely through letters between two scholars, this epistolary fantasy has a unique charm that pulls you into its deep-sea mystery and growing romance. As a debut, it’s a solid start to what promises to be a series with a lot of potential.

The story begins with a reclusive scholar, E., discovering something beautiful outside her underwater home. This sparks an intriguing correspondence with the renowned Henerey Clel. At first, their letters dive into passionate discussions about their academic interests, but soon, their feelings for each other emerge. The romance develops in a way that’s both intellectually stimulating and heartwarming.

If you're an academia lover, this book will absolutely speak to you. It demands your attention with its intellectual exchanges and slow-burn romance, though I have to admit, the entire book is made up of letters—so if you’re looking for fast-paced action, you won’t find much here until the last 20-25%, which picks up just before ending on a cliffhanger.

What really drew me in was the romance and the way we get to know E. and Henry through their letters. Their love story unfolds in such a unique way, with their siblings, Sophy and Vyerin, also writing to each other, bonding over the mystery of their missing siblings. I adored their friendship and how they shared their grief through their mutual love of books and fantasy, and I especially enjoyed their discussions about their libraries.

If you're in the mood for a slow-burn, letter-driven romance with a touch of academia and an intriguing underwater setting, give this one a go. It’s a good read that leaves you wanting more.

Thank you. NetGalley and Orbit Books for the advanced copy in exchange for an honest review. All thoughts and opinions expressed are my own.

#ALettertotheLuminousDeep #NetGalley

This fantasy novel transports readers into a richly imagined world brimming with magic, mythical creatures, and epic quests. From the very first page, the author draws you into a vivid and immersive setting, complete with intricate world-building and finely detailed lore that enhances the sense of wonder and adventure.

The plot is thrilling and fast-paced, filled with twists and turns that keep you engaged. It follows the journey of a protagonist who is as relatable as they are courageous, facing daunting challenges and making tough decisions along the way. Their growth throughout the story is well-developed, balancing moments of vulnerability with displays of strength and heroism. Secondary characters are equally memorable, each with their own unique traits and motivations, contributing depth to the overall narrative.

The author's command of imagery and description brings the fantastical elements to life—whether it’s a sprawling enchanted forest, a dark and ominous castle, or a mystical artifact imbued with ancient powers. The magic system is well-conceived, with clear rules and limitations that add both intrigue and stakes to the plot. This sense of structure helps ground the story, making the fantastical elements feel both believable and integral to the characters' journey.

I started this book a while ago, but it didn't grab me. Maybe I'll finish it, but for now I'll put it in the middle of 3 stars.

DNF at 16%. The writing was so difficult for me personally I couldn't keep up.

For an epistolary novel to succeed, each letter writer should have a distinct voice. However, the four or five characters whose letters make up the first 16% (amid a rather confusing timeline, I might add) sound nearly identical. I could have overlooked this if the writing style hadn’t been completely opposite to my taste—overly dramatic, with nearly every sentence ending in an exclamation point, making every thought seem so important that, in the end, nothing felt important at all.

If you're thinking of picking this up, I highly recommend reading a sample chapter first to see if the writing style works for you. That said, I would still give this author another chance in the future, just not with this one.

The perfect mix of fantasy and romance! With light academic vibes to fill your metaphorical cup, this book was a real treat. I loved that it was told through letters; it felt like such a unique way to get to know our characters. I also really appreciated the mental health rep in this book as I feel like it's harder to come by in fantasy novels. It was handled really well by the author and definitely earned them a few brownie points from me. I look forward to continuing with this series and I think this was a great introduction to the world!

A Letter to the Luminous Deep was an enchanting and unique read. It was the first epistolary novel I have come across, and after getting the hang of it, I really enjoyed it and found the style enhanced the story. The characters were exceedingly well written, and the mental health aspect was portrayed so thoughtfully I found it helped negate the distance I was worried I would feel from the writing style. The prose was whimsical and romantic. Sylvie Cathrall succeeded in creating a vivid underwater world that I cannot wait to return to in the sequel.

“Reading your letter was an experience like no other. Have you ever considered, E., that someone ought to write a Fantasy about you?” :’)

Thank you so much to Orbit books and NetGalley for providing me an early copy to review. I had a great time, and recommend it to fans of Emily Wilde, A Feather so Black, and cozy, otherworldly fantasy.

This was probably the most interesting book I've read. As for the plot, unfortunately it was hard to distinguish the characters based on the letter writing style and I had to keep going back to the character names. Perhaps this would work for readers who enjoy this type of genre.

Sadly, it was just not for me.

A Letter to the Luminous Deep is a novel of contrasts: it excels in creating a captivating world and offers a unique storytelling approach but struggles with pacing and emotional depth. Fans of slow-burn romances and intricate world-building may find much to enjoy, while those seeking a faster-paced plot or more direct engagement with the characters may find it lacking. The book's imaginative setting and tender moments hold promise for its continuation, making it worth a read despite its imperfections.

The epistolary format initially seems like a fresh and engaging choice, offering an intimate look at the characters' thoughts and feelings. E. and Henerey’s correspondence reveals their growing affection for each other in a tender and slowly unfolding romance. The letters, though, sometimes feel overly formal and stilted, which can distance readers from the characters and their interactions. This formality occasionally hinders emotional connection, particularly during pivotal moments like their first meeting.

The novel’s pace is slow, with a focus on the mundane details of daily life and the gradual development of the characters’ relationship. While this can create a sense of intimacy and depth, it also makes the narrative feel drawn out. The mystery of the "Structure" and the characters’ disappearance takes a backseat to the slow build-up, and the eventual revelations come after a lengthy wait. This pacing might be frustrating for readers who prefer a more immediate plot progression.

Despite these issues, the novel's final sections, where the mysteries start to unravel and the world’s complexities are revealed, offer a more engaging experience. The buildup of intrigue and the connections between the characters’ discoveries provide a satisfying payoff, though it is somewhat marred by a cliffhanger ending.

Thank you to Netgalley and Little Brown Book Group for this advanced reader's copy in exchange for an honest review.

What an interesting concept. I found the curiosities in this book fascinating, especially the exploration of the deep sea and the unanswerable mysteries it holds.

I was really intrigued by the plot and premise.

The characters seemed interesting.

However, as much as I was intrigued by the plot, the writing style just wasn't for me. It took me a while to get through this book. A majority of the book is writing that didn't seem to move the plot forward quite that much, so I struggled to hold interest. Don't get me wrong, the writing itself was beautiful, but for me personally, it didn't fully grasp me enough.

I think I would have been more engrossed if the story wasn't in letter format.

I especially found it confusing for the first third of the book when it was skipping to the different time frames and different characters. Hence why it took me a while to get into this book.

Overall, it was a very intriguing story with a writing style that wasn't really for me, which is a shame because I would love to see how this story plays out.

"My dear E.,
I have thought of nothing else but you and your letter over the past day or so, and I do not intend to start thinking of anything else anytime soon."

How did one book make me feel such a range of emotions!? Any book that centres around letters and messages is an ‘automatically add to TBR’ scenario for me, and despite a rocky start, ‘A Letter to the Luminous Deep’ didn’t disappoint.

After an event known as the Dive, our main characters live in an endless sea with only rare pockets of land, instead, man-made islands of floating homes and universities are precedent. E. lives in Deep House, the first underwater home of its kind, built by her mother and recognised for its ingenuity, but when an underwater earthquake destroys the house, it also vanishes E and her confidant, Henery. E.’s sister Sophy, and Henerey’s brother Vyerin, are left the pick up the pieces of their disappearance one year later.

I also have to add here that the rep was also fantastic, from what I can say of personal experience and just the careful inclusion. This included OCD, anxiety, agoraphobia and the many characters being queer, with both Sophy and Vyerin are in same-sex relationships.

Admittedly, it was hard to get started. I was thrown by the multiple POVs and trying to keep track of two different timelines of letters that often seemed to intersect. As well as (and I don’t normally say this) a lack of world-building-especially with the amount of academic jargon specific to the world thrown in. What made the difference when getting started was listening to the audiobook alongside reading my e-copy to get a feel for everyone and all the different voices and then switching it up as needed. It has a full cast and it brought the story to life.

I loved the characters, the writing gave a very Becky Chambers/ Heather Fawcett feel and I enjoyed falling in love slowly with all their quirks, plus hearing their hopes and dreams told in letter format was both eloquent and heartbreaking at times. I enjoyed how Sophy and Vyerin are brought together through the tragedy and that, although the romance rep is so cute, friendship also played such a large part in the tale. It gave academia/found family vibes (my fav).

I was a bit confused (and still am) about what was happening at times and quite how it ended (but by the end I was so invested in the character arcs to worry too much). Plus, although the majority of the plot features a bit of mystery but mainly different romance and friendship, I genuinely did gasp at twists towards the end. It didn’t help I had no idea this wasn’t a standalone, I was shook and still need the sequel ASAP.

I can’t wait to get my hands on the sequel and whatever the author writes next.

A really unique story idea that was so enhanced by the use of the epistolary format. A joy to read and highly recommended.

3.5 stars

after the first few chapters, I soft-dnf'd this book. while I was intrigued by the writing style, I was not really in the mood for this type of story at the time. then yesterday, I picked it up again, and I'm so happy I did!

what I really liked:
🪸 original & beautiful writing, in the forms of letters and notes
🪸 disability rep (neurodivergent MCs)
🪸 mystery
🪸 scholars talking about their research

but I have to say, it is not an easy story to get into, especially without a glossary. but once you get used to all the terminology and the worldbuilding, it is a magical journey indeed. I can't wait for the second book!

Epistolary novels are SO fun! I think I will enjoy almost anything written in letter format that is at least a tiny bit cosy. I'm really glad I read this one.

I tried to read this, twice. Both unsuccessful. Something about the writing felt like blocking me out🥲 i couldn’t connect with the story at all. Quite disappointing since this was marketed to be perfect for Emily Wilde’s fans…

I really wanted to love this but sadly it just didn’t work for me.

I’ve never read a book that is solely made up of letters, it was an interesting concept but it meant that the actual plot took a long time to get going. I also didn’t get much of a feel for the underwater setting. I might try again as I think reading it a second time when I already know where the plot is going it things might work better.