Joint Review: “What Stalks the Deep”

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Book: “What Stalks the Deep” by T. Kingfisher

Publishing Info: Tor Nightfire, September 2025

Where Did We Get This Book: Netgalley!

Where You Can Get This Book: WorldCat.org | Amazon | Indiebound

Book Description: Alex Easton does not want to visit America.

They particularly do not want to visit an abandoned coal mine in West Virginia with a reputation for being haunted.

But when their old friend Dr. Denton summons them to help find his lost cousin—who went missing in that very mine—well, sometimes a sworn soldier has to do what a sworn soldier has to do…

Previously Reviewed: “What Moves the Dead” and “What Feasts at Night”

Kate’s Thoughts

I have found myself repeatedly charmed by T. Kingfisher’s stories. I think that once I figured out that they’re less scary (though there are certainly some scary beats to some of them!) and more cozy in their horror-esque elements and just embraced it it clicked into place, and because of that I was interested to see what she was going to do with another “Sworn Soldier” novella. I like Alex Easton as a protagonist, I like the world that she has built that is of our own but with some tweaks and differences, and I was curious to see what kind of horror theme we were going to get this time. And she had me at caves, because MAN do caves freak me out.

“What Stalks the Deep” is another kinder gentler horror tale from Kingfisher, and while I think it’s probably the weakest of the series for me thus far I still found it to be enjoyable and at times tense. Alex Easton has fought in wars and seen strange and dreadful things over the years while being a Sworn Soldier for Gallacia, but they still have their personal anxieties, and going to America to look for a missing person in a remote cave system in Appalachia is one of them. It was interesting seeing Easton in a wholly new environment and culture, as The U.S. and Europe are certainly filled with differences, and I thought it was a really cool choice to have Appalachia with its mysteries and general otherworldliness adding to it.

I don’t want to spoil much here, as I think Kingfisher deserves to have the build up and the reveals, so when talking about the horror bits I’m going to be as vague as I can be. In terms of the supernatural, this felt a bit like a spin on John Carpenter’s “The Thing” but maybe by way of “E.T.” as opposed to the body horror scares of that film. I liked Easton and their new compatriots trying to figure out where the missing man Oscar ended up, be it lost in a cave or perhaps something worse, and I liked that we had some pretty claustrophobic moments in the cave itself. Much like what I referenced above with “The Descent”, the true horrors in this book are more about the perils of mining and caves and the unpredictability of both.

I am very pleased that the “Sworn Soldier” series is continuing! T. Kingfisher continues to have really creative stories for a really charming protagonist.

Serena’s Thoughts

I completely agree with Kate’s assessment that much of the true horror to be found in this book comes from the cave itself. There is plenty of time and focus devoted to the many ways that a coal mine can kill you. And that’s not even getting into the sheer claustrophobia-induced terror that comes with vivid descriptions of crawling through tight spaces, not knowing what’s ahead and without the ability to turn around.

Beyond that, I continued to enjoy Alex as a main character. Endlessly practical with many believable foibles (such as the instinct to volunteer to do what we least want to do just to prove something to… someone…), Alex is a sympathetic and hilarious narrator. This one was all the funnier for the snide observations of American behavior. (Alex has strong feelings about our propensity to shake the hand of everyone around us.)

The monster in this one wasn’t quite as terrifying as the ones found in the first two books, perhaps. That said, it did follow a trend seen in many of Kingfisher’s horror novels—that is, the ability she has for creating creatures that are at once horrific and terrifying, but who, through some combination of childlike ignorance and sadness, are also bizarrely sympathetic. It creates this odd emotional state in the reader where you both want Alex to succeed in getting rid of this horrible thing, but are also slightly sad that it had to come to this in the first place. Without getting into spoilers, I was happy with the direction one aspect of this took in this book in particular!

Overall, I very much enjoyed this latest entry in the series! I think I enjoyed it a bit more than Kate, so I’ll bump this one up in my rating!

Serena’s Rating 8: It’s so weird to both be terrified by the monster but also kind of wanting to pat it on the back and tell it “it will be ok??” Another excellent entry!

Kate’s Rating 7 : With echoes of “The Thing” but without the dread (though the claustrophobia is scary on its own) and another strange mission for our charming protagonist, “What Stalks the Deep” is a fun entry in the “Sworn Soldier” series.

Reader’s Advisory

“What Stalks the Deep” is included on these Goodreads lists: Novella Length Fantasy & Sci-Fi and Perfect Reads for All Hallows’ Eve.