What Stalks the Deep (Sworn Soldier, 3) by T. Kingfisher

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RELEASE DATE 9/30/25

The next novella in the New York Times bestselling Sworn Soldier series, featuring Alex Easton investigating the dark, mysterious depths of a coal mine in America

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...