In the second book of the Sunken Archive duology we follow E. and Henerey beyond their world and into a new underwater city. When they discover that they may not be able to return home, the reclusive scholarly pair come to embrace their new circumstances. But from the other side of the world, their siblings are still trying to reach them. When the two worlds collide and the whole group learns the truth about a fast-approaching threat, they’ll have to balance the need for survival versus the world they left behind.

This is such a unique, creative world the author has created. The characters and settings are beautifully written and the story is unlike anything I’ve read before. The book is written from the perspective of multiple characters in the form of letters and memos, which can initially take some getting used to. But once you get into the rhythm of the writing style it is easy to get lost in the world the author has created. A great book for lovers of fantasy!

A Letter to the Luminous Deep was one of my favorite reads of last year. I absolutely adored it and was so excited to get an early copy of the last book in the duology. This book did not disappoint. Sylvie Cathrall has created such a fascinating world in these books. But nothing tops her lovely characters. E and Henerey are so dear to me. The sweetest nerds you have ever met and their love story just fills my heart. The mental health representation is handled so well. There was a very interesting escalation in stakes for this book. I can't believe we are done with this story. I can see this being a duology that I revisit frequently. I can't wait to see what Sylvie Cathrall does next. She has earned a fan for life.

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

This was a decent follow up to the first one. I love the style of writing in these books and the letters, but the plot drug on and didn't wrap up in a satisfying way for me.

While I didn’t end up enjoying this one quite as much as the first, I’ll say at the start that, all things considered, this is a wildly creative and beautiful duology! It’s especially successful in its depictions of anxiety and mental health, as well as its use of “historical” or “academic” language.

This book picks up pretty much right where the previous one left off. But unlike the first one, which slowly built to its action, this one came in hot right from the start! Immediately, we begin uncovering so many new layers of history and magic that make up this world. Like E. and Henerey, the reader is left trying to piece together what exactly is going on, always just on the cusp of understanding, without being able to put the entire puzzle together until the end of the book. I had a few theories here and there, but not only was I wildly off base most of the time, but I never even got close to guessing how things would finally wrap up!

I also continued to greatly enjoy all four of the main characters. As I referenced above, this book stands out for its incredible representation of mental health and struggles with anxiety. E.’s journey is one of self-discovery, self-acceptance, and coming into her own, compete with her unique strengths! Her struggles were never hand-waved away, but they also didn’t define her. And E. herself had much to say when others began seeing her only through this lens. It was honestly refreshing. I feel like I’ve read a number of books that have attempted to tackle mental health, chronic pain, or similar struggles. But too often authors seem to create characters whose only personality or sense of self is completely wrapped up in this one aspect of themselves. E. acknowledges and explains her own limitations, but we also see her continue to push her own boundaries, always trying to find new ways to follow her passions and dreams.

I also really enjoyed the continued romance between E. and Henerey. This is the kind of cozy fantasy that I enjoy. It’s soft, quiet, and respectful. But it also wasn’t dull, without exhaustive details about mundane everyday events. Theirs is an untraditional love story, but it was all the more beautiful for it!

I also continued to love the writing style of this book! As a lover of historical fiction, I’m always drawn to this sort of verbose style, full of long, complicated sentences and large vocabularies. I also think the use of the epistolary style works really well. The action is definitely on the slow side, but by telling the story in this format, the author was able to set out little clues that the reader would have to then wait to put together as more information was slowly doled out via various other letters or journal entries.

I will say, however, that this book didn’t quite reach the highs of the first book. I enjoyed all the reveals about the greater reality of these characters’ world and histories, but because this information didn’t come until the very end, the reader has to live with a lot of questions for the majority of the story. The pacing was also a bit too slow towards the middle of the book. I was invested enough in the characters and the writing itself to be carried through this lull fairly easily, but it was a notable difference between this one and the first, which was so tightly paced.

Overall, this was a fantastic sequel! So many mysteries were explored and revealed, and the duology concluded in a way that I truly could never have predicted. If you enjoyed the first book, definitely give this one a go! And if you’re a fan of cozy fantasy and enjoy a historical-feeling writing style, this is definitely the duology for you!

Rating 8: Pure whimsy and lyricism, with a lovely understated love story at its heart!

Link will go live on The Library Ladies on May 28

What a wild ride the Sunken Archive duology has taken me on. I enjoyed the first book, but I absolutely ADORED the second one. Henerey and E. have my heart. I love them both so much and their relationship has truly bloomed into the most beautiful thing. Sylvie Cathrall has created a world like none other I have read before. The prose is beautiful, I love all of the characters, and the world is breathtaking. A Letter from the Lonesome Shore was the perfect end to an equally beautiful beginning.

This ARC was provided by Orbit Books via NetGalley in exchange for an honest review.

I ended up not finishing A Letter from the Lonesome Shore at 38% of the story. At this point, I feel like I've read enough. The first book A Letter to the Luminous Deep really struck my fancy and I enjoyed the mystery that the siblings of E. and Henerey attempt to unravel through their letters and automatic posts. Vyerin and Sophie had such a great connection and I genuinely enjoyed that story. A Letter From the Lonesome Shore picks up what happened to E. and Henerey from their POV through their letters back home as well as the introductions of other POV characters. And I was bored out of my mind. Cathrall really delved into the cozy and there were multiple chapters of just the day to day existence of E. and Henerey. There was a mystery hinted at and there are some stakes, but they just felt buried under endless fluff. At this time, I'm just not interested in actually seeing that mystery solved because I just don't care about these characters anymore. The magic of what happened to them is gone.

Thank you to Orbit and Netgalley for the arc for review purposes.

Thank you NetGalley and Orbit Books for the opportunity to read and review in exchange for honest feedback.

This is the beautiful conclusion to the Sunken Archive duology. It's everything I wanted in the series. Slyvie Cathrall's writing is simply enchanting. In the first book, we followed Vyerin and Sophy as they mourned their lost siblings and their subsequent quest to find them as they felt they were truly lost and not deceased. Now, a year and a half later, we see what E. and Henery were up to in all that time Vy and Sophy were trying to find them. It's full of the beginnings of falling in love, mystery, and academic rivalry.

I absolutely love Cathrall's inclusivity. She manages to capture what it's like for people on the asexual spectrum to fall in love so well. Her books also easily include every representation of relationships you can see in life and it's beautiful. This book was just as sweet, fun, intriguing, and wonderful as A Letter from a Lonesome Shore. I feel so honored I got to read it early.

“A Letter to the Luminous Deep” was one of my favorite books of 2024 so I was thrilled to be granted an ARC of the second part of the duology, “A Letter from the Lonesome Shore”. This book picks up right where the previous volume left off continuing the adventures of both E and Henery and their respective siblings. Definitely check out the first book before starting this one - nothing will make any sense without having read book one.

I have to admit that I’ve been struggling to rate this book. On the plus side I’ve fallen in love with Sylvie Cathrall’s writing style and I loved the epistolary format of this novel. The characters were amazing and despite a large cast each one felt unique and real. Henery and E were absolutely adorable in this book and I enjoyed watching them explore their growing relationship as much as I enjoyed watching them explore their new surroundings. I enjoyed the addition of the Scholars and particularly liked the Thirtieth Second Scholar. I also found the world building to be very unique and most of my questions about the setting were addressed by the end of the book.

However, I struggled a lot with this book due to the pacing. For about 70% of the book the characters are told repeatedly that there’s something seriously wrong with the world but the main cast shows absolutely no concern about this. Moreover the reveal and resolution of the issues are handled in just a few chapters. There’s somehow no tension despite the world ending implications and yet also no room for anything to breathe with how quickly things are resolved. Perhaps if the author had expanded the Antepelagic documents section and woven them through out the narrative it might have improved the tension and pacing. Regardless, I would love to know more about the world before the Dive and would devour a prequel novel set in the Antepelagic world.

This duology is utterly unique in world building and first class in writing and character development. I’m excited to see what Sylvie Cathrall does next - she’s become an automatic read author for me and I highly recommend this duology.

Thanks so much to NetGalley and Orbit for the ARC in exchange for an honest review.

Thank you to NetGalley for allowing me to read this book before its publication date.

I was so excited to get to read this sequel. I really enjoyed A Letter to the Luminous Deep, so I had high hopes for the sequel. Lonesome Shore started a little bit slow, but I soon found myself relaxing into the world again. The characters are so genuine, and the writing style slowly washes over you if you give it time.

3 stars 🐋✨

Thank you to NetGalley and Orbit for sending me this ARC in exchange for an honest review!
Expected Publication Date: May 6th 2025

A Letter from the Lonesome Shore is a whimsical and unique fantasy told through letters, journal entries, and other media. The writing is beautiful and descriptive but formal. My one gripe with this writing style is that there isn't an obvious tonal shift between the characters. They all write the same and had the same personalities, to the point that I genuinely could not tell the characters apart. In a book that relies solely on correspondence to carry the plot, distinct personalities in writing is a must. I think because of this it was difficult for me to connect with the characters and thus to connect with the plot.

Oddly enough, I might reread this after rereading book 1 - I'm curious to see if my opinion changes with a fresh memory of book 1 because it is truly a beautifully written duology.

3 Stars
One Liner: Well… I wish I liked it better

Sophy and Vyerin, respective siblings of E. and Henerey, finally figured out what had happened. Now, they are on a mission to search and bring back their loved ones. They even discover the elusive Entries. However, before they can succeed, an ancient cosmic threat could destroy everything.
Will the siblings reunite, and can E. and Henerey have their HEA without any threats looming overhead?
This is an epistolary novel and comes in a series of letters, journal entries, notes, records, etc.

My Thoughts:
This is not a standalone. You have to read the previous book before you get to this. As much as I want to tell you that you should read them together, I won’t. The pacing is so slow that back-to-back such books could put you in a slump. Space books #1 and #2, with a couple of quick reads in between.
In a way, this book does feel easier to read. However, it is also a chore. There’s a bit of intrigue about what the danger is or what could have happened, but honestly, it takes too long to get to the point. This was okay in the previous book since it set the stage. Here, there isn’t enough plot for a 400-page book, and yet, it feels like I’ve read an 800-page tome. In short, it drones on and on.
The bits with E. and Henerey are still adorable and made the book more bearable. Scholar 30.ii is also cute in a bumbling way. They brought some much-needed lightness to the narrative.
Also, imagine a world where being on time for an appointment means they arrive four hours early! Sounds funny until they knock on your door at 4 AM because you planned to meet at 8 AM. Still, the scene made me laugh.
Since the whole thing is essentially notes, letters, and records, there’s a lot of stream-of-consciousness rambling, which goes overboard in many places. Just because something is fun to write doesn’t make it fun to read. Sorry, I say this as an author myself.
The mental health rep is wonderfully done. It shows the situations without making it preachy or OTT. There are other themes like the dark side of academia, fear of the unknown, restrictive perspectives, personal prejudices, influence, etc. None of them feel forced, so that’s a good thing.
I liked meeting the mysterious sea woman again. Wouldn’t have minded if she had more space.
The world-building is interesting. There are details, though not enough to explain everything. In a way, this is good. The book is a slog as it is. However, I could visualize the domes, the library, the underwater garden, the rooms, etc. No complaints here.
It takes way too long to get to the Antepelagic insights, the backstory, and stuff. The Predator doesn’t feel the least bit scary either. In a way, it’s good that he isn’t mentioned often.
The climax and ending are… lackluster… bland and underwhelming. Not that I expected anything big given the tone so far, but what we get is just too weak to make a proper impact. I can see why it ends with that entry. It’s a saving grace for those who enjoyed the book more for E. and Henerey.

To summarize, A Letter from the Lonesome Shore has a few nice things to offer, but doesn’t give the same experience as the previous book, despite offering a conclusion. I wish I enjoyed it better!
Thank you, NetGalley and Orbit Books, for the eARC. This review is voluntary and contains my honest opinion about the book.

This was such a whimsical and magical read that was so beautiful and fun to get right into! I loved the mental health rep in this book and the characters were really written in a way that made them relatable to the reader.

The story and the plot were so well fleshed out, I fell in love with Sylvie's style of writing instantly!

Thank you NetGalley for an eARC!

The description says this is the conclusion, but there could be more with how this left off. Just like the first one, I really liked the format for these characters. While I am not typically a huge fan of letters in stories, in this it just feels so right and gives great insight into everyone involved. This was a wonderful journey and I hope to see this author do more soon.

Note: ARC provided by the publisher via Netgalley in exchange for an honest review.

4.5 stars

“A Letter to the Lonesome Shore,” sequel to “A Letter to the Luminous Deep,” is the latest addition to The Sunken Archive series. Picking up where the first installment left off, we follow Henerey and E to a strange underwater city with its own customs both strange and familiar. Sophy, Vyerin, and Neia have figured out where their missing family members have gone and work to find a way to follow them to their destination. I really loved watching Henerey and E translate their relationship from a courtship by letter to a real-life relationship. They are both such kind and wonderful characters that face their own struggles, and watching them support one another in a strange environment while falling in love was so beautiful. I also loved the addition of several new characters, particularly the Thirtieth Second Scholar, who was an absolute delight. The representation for people with mental health conditions as well as the LGBTQIA+ community in these books is absolutely wonderful and so special to read about. Sylvia Cathrall has created a delightful world reminiscent of Jules Verne and romance that calls to mind the Emily Wilde series. The Sunken Archive is not to be missed!

In A Letter from the Lonesome Shore we pick up right where A Letter to the Luminous Deep ends. I can't give away anything without spoiling A Letter to the Luminous Deep so I will leave the summary there.

I enjoyed A Letter to the Lonesome Shore very much! I loved being back with these characters I had grown so fond of and seeing the next part of their story. Cathrall's use of language is so beautiful, I revelled in each word. The prose was lyrical without being overly saccharin. The world Cathrall creates is vast- somehow even more vast than I even realized in the first book- and is one I'm excited to continue to explore in future books.

I HIGHLY recommend this series and look forward to continuing the journey with these characters in their ever expanding world.

Thank you to NetGalley and Orbit Books for providing me with an ARC of this book in exchange for an honest review!

"A Letter from the Lonesome Shore" was an enchanting and deeply gratifying conclusion to this duology! Author Sylvie Cathrall creates a magical, unique world in this series that captures your attention from the first page. Our favorite characters from the first installment return, and we get to meet new personalities along the way. We return to this extraordinary world on the ocean, and pick up right where we left off in "A Letter to the Luminous Deep". E. and Henery have gone through the Entry to seek whatever awaits them on the other side. They are eventually rescued and taken to a city entirely underwater, a small haven located in what is seemingly another world.

As they meet the inhabitants of this strange place, E. and Henery begin to realize that returning home will not be a simple task. The inhabitants are all First and Second Scholars, and it becomes clear that they are sitting on vital information about E. and Henery’s world. As the duo plans to figure out what is going on, we follow along with Sophy, Vyerin, and their crew as they seek out Entries in the hopes of finding their siblings.

Throughout the novel, we watch as E. and Henery fall more in love–they have a charming, heartwarming romance, and I loved seeing it unfold. E. grows more confident in herself and her actions, a change from the girl we meet in the first book. Her character arc, especially how it culminated in her decision at the end, was supremely satisfying. I also adored the love she has for Sophy, and Sophy’s love for her. To me, that is the driving force of this duology. Sophy and Vyerin’s correspondence and resulting investigation all occur because of Sophy’s grief for her sister. And after all, grief is love with nowhere to go.

“My sister was brave enough to make this choice on her own, so I will follow her lead.”

Like "A Letter to the Luminous Deep", this is an epistolary novel, told through letters, journal entries, and other written works. While this format is enjoyable to read, it does have its limitations. The one I struggled with the most was the order of the letters. The beginning half of the book was nearly entirely E. and Henery, whereas the latter half mainly included Sophy, Vyerin, and Niea. I found myself growing tired of the same characters writing back and forth for long periods of the book. Despite that, Cathrall included a variety of documents that made the story entertaining and provided the reader with necessary context. I greatly enjoyed learning about this new world that E. and Henery stumble upon, as well as the history of their own world and the universe they inhabit.

My only complaints about this book are the same from the previous. The writing is verbose and overly formal, making it difficult to read on occasion. Each character lacks their own distinctive voice, so nearly all the letters read the same. While many of my worldbuilding questions were answered, I would still love more information about what occurred after the Dive and how their world advanced. Lastly, while this book was overall a satisfying conclusion, I could not fully appreciate part of the ending. It was a bandage, not a cure; I believe E. could have lived up to her true potential but fell ever-so-slightly short. Despite that, the true ending of the book and final documents included were heartwarming and perfect for our main characters.

Overall, my review and feelings are overwhelmingly positive! I would absolutely recommend this series to anyone looking for fantasy in a unique setting with memorable characters and love woven throughout the tale.

A Gentle, Thoughtful Ending to a Unique Duology

A Letter from the Lonesome Shore is a quiet, meandering, and deeply heartfelt conclusion to the Sunken Archive duology. This novell is picking up right where A Letter to the Luminous Deep left off - we finally get to see E. and Henerey together—not just through letters, but side by side, navigating life in a strange and whimsical, new world.

The relationship between them is beautifully written. They’re still awkward, still tender, still afraid of being too much for each other—and still written so beautifully. Their dynamic doesn’t magically “fix” anything about them, and that’s part of what makes it feel real. There’s a ton of warmth and quiet understanding in how they grow into their relationship.

Sophy and Vyerin’s journey searching for their siblings adds some muchneeded movement to the story, though I did find the pacing a little slow; however, this story is low-stakes fantasy. The plot isn’t quite as tight as the first book's. There is less mystery and more reflection. Some of the more cosmic, endgame revelations didn’t land for me emotionally, but the writing itself remains as lyrical and gorgeous as ever.

This series won’t be for everyone. It’s heavy on mood, introspection, and letter-writing, and light on action. But if you liked book one, and especially if you appreciated its mix of emotional honesty, quirky academic worldbuilding, and quiet magic, this is a satisfying and emotionally rich wrap-up.

I look forward to Cathrall's future stories!

Thanks to NetGalley and Orbit for the advanced copy.

While I did not enjoy the second book in the Sunken Archives as much as I enjoyed the first it was a very good read. I missed the gentle longing in the letters between Henery and E. While this book also told the story as a series of letters, I felt that the connection between the characters wasn't as strong.

3.5* Rounded Up

I overall enjoyed this book but not nearly as much as I loved the first one in this duology. I think for me the pacing was way too slow and that maybe the letter format did not work quite as well as it did in the previous book. I had so many questions after the first book and though we did get those answers it wasn't until like 75/80% of the book. I did end up liking the idea and the uniqueness of the answers we did get to this world and it really made me think about the universe and what we know about it. So overall I did enjoy it but I just wished it had a bit more of the charm/excitement as the first one did for me.

I received an eARC thanks to Netgalley and Orbit, all opinions are my own.

When I finished “A Letter to the Luminous Deep”, I was so excited to get my hands on the next book to understand more about this world envisioned by author Sylvie Cathrall. I was not only deeply emotionally invested in the outcome of the lives of E., Henery, Sophie, and Vyerin but I was also deeply curious to learn more about their expanding world!

“A Letter from the Lonesome Shore” not only satisfied my curiosity while still leaving a few loose ends for my own imagination to explore, but more importantly to me each character arc found a place of closure.

Although marketed as a “cozy romantasy”, that’s not how I would characterize these books. There is more excitement and mystery here than the word “cozy” implies! The world Cathrall paints for us is fascinating and dangerous. There are real risks and our characters face a great deal of unknown. And while there is a romance at the heart of this narrative, there is so much more!

I think a more accurate term might be “wholesome fantasy” (though perhaps that is harder to sell!) In addition to a beautiful romance, there are deep family bonds and love that reaches through the bounds of time and space. There are multiple stable, mutually-respectful, healthy long-term relationships on display. There are reasonable boundaries with family members who are loved, but who are not always respectful; and there is work towards and hope for reconciliation.

Finally, I found it so meaningful to read from the point of view of a character with a mental illness, written by an author who also struggles with a “Malady of the Mind” (as E. calls it). E. is a lot more than her “Malady of the Mind”, but we are shown how it impacts her daily life and experience a portrait of her as a whole person, not a label or a diagnosis. Her mental illness is real, but it is not her, and that is beautiful and powerful to see.

In short, my only possible complaint about this book is that I wanted more of it. Please send recommendations, anyone, and please write more wholesome fantasy, Ms. Cathrall!