A Letter to the Luminous Deep is a book that should have been so far up my alley it was knocking on my back door ready to come in for a cup of tea, and instead it didn't work for me at all. I'm writing it up partly because I think the ways it (imo) failed are interesting, and partly because tastes differ and I suspect some of you may enjoy it very much.

Okay, so. The premise, which is what hooked me initially, is that this is an epistolary story about fantasy deep sea exploration and sibling bonds. It's set in a world in which there is no land except a single atoll; long ago, people lived in sky cities, but some kind of cataclysm ended that, and now everyone lives either on the atoll, on floating residences of various sorts, or (fairly recently) in underwater habitations. One of these is the Deep House, the deepest underwater home yet made.

A year before the start of the book, reclusive E. Cidnosin began writing to shy scholar Henery Clel; E. lives in the Deep House, which her mother built, and Henery is fascinated by the Deep House and the largely unexplored depths of the ocean. The two of them grow increasingly close, and then, at some point and in some way, die or vanish -- it's not initially clear which. Whatever it was, a year later, E.'s sister Sophy and Henerey's brother Vyerin strike up a correspondence and begin to trade their siblings' letters and journal entries and so on, along with their own letters, bonding as they try to discover what happened to their beloved siblings. The story thus unfolds in two timelines, as Sophy and Vyerin go through E. and Henerey's writings sequentially and share their own thoughts and reactions. Some of the letters they're sharing are their own from a year ago, written to their siblings at the time, so for Sophy in particular we get past and present events intertwined. (In the one-year-ago timeline, Sophy was on a scientific expedition to a deep marine trench, though busily writing letters to E. about it.)

It's a really cool conceit! Other things I like: ( very mild spoilers )

...And unfortunately, that's pretty much where it stops, in terms of what worked for me. ( from here on out this gets more negative, with some vague but not detailed spoilers )

I think part of my problem here is that I love domestic stories, and I love books with very low, personal-level stakes, and I love books about ordinary people having everyday struggles, and I love books about hope and the restorative power of kindness... but I also believe in the power of misunderstandings and petty frustrations and supply chain logistics and all the bits of sand in the gears of life, and so I absolutely bounce hard off a lot of the books currently being written as "cozy," and this is another victim of that. I wanted a domestic epistolary story about siblings and the material culture and scientific inquiries of an ocean world; I got coziness that, unfortunately, felt like cloying cotton candy to me. I suspect that some of you would react similarly, and for others, what I found cloying would be charming and relaxing coziness. And that's clearly what the book is aiming for, so if you're in the latter camp, I hope you have a great time with it!

Me, I'll just spend a moment pining for the book I wanted it to be, which is not the same as the book Sylvie Cathrall wanted to write.