Review - What Stalks the Deep by T Kingfisher

What Stalks the Deep (Sworn Soldier, 3) 

T Kingfisher
Titan Books, 30 September 2025
Available as: HB, 192pp, audio, e   
Source: Advance copy and bought
ISBN(HB): 9781803369716

I'm grateful to the publisher for  giving me access to an advance e-copy of What Stalks the Deep to consider for review.

In this, the third part of kis adventures, Alex Easton, former soldier (and still suffering from that) in the army of Galicia, an obscure Central European country where military service (ie being a 'Sworn soldier') determines gender, gets to visit the USA.

Easton answers a call for help from Dr James Denton, who shared an earlier adventure with Easton. Denton's cousin has gone missing in a disused coal mine. Now Easton suffers from claustophobia, so of course he feels duty bound to assist his friend despite the weird, supernatural goings-on down the mine...

What follows is a fun, if creepy, exploration of a mystery that brings with it danger, exploration in cramped, inaccessible tunnels, revenge, prejudice and an ethical dilemma. The book reminder me in a sense of a Doctor Who adventure. At the risk of slight spoilers, I'd say that whereas in the previous parts of this series, Easton has confronted outright, malign, evil of a supernatural or at least fantastical sort, here the "monster" is a more nuanced being. That's important. because it presents, as I have said, a moral dilemma. But Easton's experiences in What Moves the Dead and What Feasts and Night, overlaying kis PTSD (to use the modern term, the one used here is 'soldier's heart', an older version of the same thing) have made kim defensive so there's a personal challenge here too: hitting out is an all too common reaction to stress or danger.

(And that might also apply to other characters in this book).

Plus of course, there's that fear of enclosed places to overcome...

An intelligent, scary book which is a good addition to this series.

For more information about What Stalks the Deep, see the publisher's website here.