
What Stalks the Deep is a very well written trippy fantasy historical-horror lite, the third adventure for these characters, by T. Kingfisher. Released 30th Sept 2025 by Macmillan on their Tor Nightfire imprint, it's 192 pages and is available in hardcover, audio, and ebook formats. Paperback format due out from the same publisher in Sept 2026. It's worth noting that the ebook format has a handy interactive table of contents as well as interactive links and references throughout.
This time Alex & co. wind up on a missing person case with decidedly abnormal things-that-go-bump-in-the-night aspects. Dismemberment and disappearances, cagey locals (it's set deep in remote Appalachia), and a claustrophobic and mysterious cave system attached to a mine. Although it's the third book in the series, it works perfectly well as a standalone, and readers won't have any trouble staying with the story.
The author is exceedingly talented and this story is engaging, atmospherically creepy in places, with some jump scares and some body horror including animals (bear, dog, etc) but overall nothing really horrible (probably not enough actual horror for die-hard horror fans).
Four stars. It would make an excellent choice for public library acquisition, home library, or a great weekend or buddy/binge read.
Disclosure: I received an ARC at no cost from the author/publisher for review purposes.








