“Have you ever considered, E., that someone ought to write a Fantasy about you?

You experience something unprecedented, you venture to the library in search of new knowledge, you discover a mysterious familial connection to said knowledge, and then you write all about it to a most peculiar man who does not deserve your attention – surely that is the very stuff of stories!”

In the depths of an underwater world two strangers find one another through the magic of the written word. A Letter to the Luminous Deep by Sylvie Cathrall is a debut filled with heart-warming romance, wholesome characters and a world that wraps readers in curiosity and awe.

After an event known only as the Dive, the world changed beyond recognition and became one of endless seas with only a rare few islands in sight. E. Cidnosin lives in Deep House, the first underwater dwelling of its kind which her late scholarly mother crafted. When E. makes a discovery through her porthole window it urges her to reach out to Scholar Henerey Clel to see if he can offer professional insight into what she observed. Over the course of many correspondences E. and Henerey revel in their mutual mystery as they try to unravel all that they learn and a tender and endearing relationship also begins to emerge from its shell. Yet tragedy befalls in the form of a seaquake which sees both E. and Henerey caught within its grasp and disappear. A year passes and with very little information about what exactly happened, E.’s sister, Scholar Sophy Cidnosin and Henerey’s brother, Navigator Vyerin Clel decide to share their siblings’ letters from that time in the hopes that they can finally solve the conundrum which haunts them both. 

From the beginning the worldbuilding absolutely mesmerised me as Cathrall presents us with this underwater world in which a society of scholars and intellectuals, with their three factions of campus—Boundless, Intertidal and  Atoll, and with their own distinctive historical feats, have made this uninhabitable place their home. I didn’t think a world could be so fully visualised through the medium of letters but I was happily proven wrong. The descriptions of Deep House in particular were delightful; a fully functional underwater living space, equipped with a kitchen, bedrooms, a studio, and even a library, was absolutely fascinating to picture. Through E.’s perspective we see it as a warm place where she, once with her two siblings and then completely alone, made fond memories. I imagined living surrounded by sea creatures, vibrant coral and having the sea-bed as your garden would be equally beautiful and relaxing as it would utterly terrifying. Cathrall also treats us to exploring more of this world by having included Sophy’s letters to E. during her time in the Ridge Expedition which again was fascinating to read about but diving into the dark abyss also sounded horrifying! I just loved that there were quirky little inclusions such as mail-boats delivering the letters and waterproof stationery which could be bought at a market to add even further richness to the people’s wondrous watery lifestyle. However, the narrative is a real slow burn where events gently unfold with very little amounts of action or moments of dire peril, and yet my interest never wavered. Every aspect kept me turning the pages eager to discover details about these characters’ lives and even the family drama they experienced. Surprisingly for me, this was just the kind of cosy fantasy I adored.

Cathrall’s prose throughout her epistolary novel had a formal yet atmospheric and poetic quality to it that I immediately fell in love with. As we traverse through Sophy’s letters to Vyerin and vice versa their tone is never weighed down by their grief, having had a year to dull the pain somewhat, but you can still sense their loss by the way they talk so fondly of their siblings. In their mutual ‘project’ they both get to know their siblings in refreshing ways, through different eyes, and when coming across new information both express much regret or guilt that they never knew this when their siblings were alive. Through this whole experience a close friendship between Sophy and Vyerin unfolds as they share snippets of their own personal lives, with Sophy detailing how she met her wife and Vyerin expressing how encouraging his husband is, they both express their joys and their shared sorrow, which was warming to see. Similarly E.’s letters to Henerey also conveyed much of their emotions as their first few writings were filled with hesitations, formal politeness and a sense of nervousness. When that begins to fade away into the background their letters not only grow in length but also in familiarity—a sense of comfort that they can confide their innermost personal thoughts with one another and a deep understanding ensues.

“The sight of your handwriting – and your ever-transporting words – brought about a great calm within me. How marvellous that an unexpected letter introduced me to someone who seems to see the world exactly as I do! All I can do is thank you for your kindness and pray that I will not frighten you away with my melancholic thoughts.”

As I have mentioned, at the centre of this tale is essentially a love story between two strangers who fall for each other through the magic of words. It was just beautiful for E., a person who suffers from OCD and severe anxiety, making social gatherings and face to face interactions rather traumatic, to find that the safety words upon a page could allow her to open up to someone like Henerey who also suffers from some mild social anxiety and may just sympathise with her more than she thinks. With each letter I loved reading a sense of trust form between them, a confidence in E. that grows as she goes into detail about her thought-processes and how her Brain fixates on things, the way her mind tries to make her believe every calamity it conjures up. In turn Henerey is beautifully wholesome in his understanding and acceptance and support. We need more of this in the world. Aside from the romance there is also the love between siblings explored, with E. and Sophy having the most close-knit sisterly bond, and their relationship with their eccentric brother Arvist echoed a lot of my own feelings towards my brother, who can also be an insensitive pain! Vyerin and Henerey contrasted each other in many ways but they too shared a closeness despite being tides away from each other for most of their adult lives. Cathrall certainly makes the reader see just how powerful and impactful words can be. 

“Should you find yourself growing anxious, with troubling thoughts blossoming in your mind, I would recommend focusing on the intricate details of the Fan Coral – trace each spiny, skeletal sclerite from the root to the tip – and pretending that each bubble you see outside your depth-craft is a pernicious Thought floating out of your head and into the open ocean.”

A Letter to the Luninous Deep is an epistolary novel that is deeply romantic and achingly beautiful in every way. Cathrall is an author who delves her readers into a fantasy with both warmth and charm whilst tenderly revealing a story of unsettling discoveries and tragic loss. This is truly a superb debut.

ARC provided by Nazia at Orbit Book—thank you immensely for the copy. All quotes used are taken from an early ARC and are subject to change upon publication.

A Letter to the Luminous Deep is due out 23rd April 2024 but you can pre-order your copy on Bookshop.org