Retired soldier Alex Easton, formerly of the Gallacian army, receives word that kan[a] childhood friend Madeline Usher is dying.

Ka journeys to the Ushers' ancestral home in Ruravia and finds it in disrepair, surrounded by fungus and a dark, unsettling tarn.

Publishers Weekly praised Kingfisher's "standout character work and scenic descriptions that linger on the palate", calling the novel "thoroughly creepy and utterly enjoyable.

"[1] Writing for Booklist, Erin Downey Howerton called the novel an "infectious new spin on classic Gothic horror", stating that it "will lure fans of classics like Henry James's The Turn of the Screw, as well as those who like modern environmental terror like Jeff VanderMeer's Annihilation (2014) and English folk horror movies like In the Earth (2021).

"[2] Writing for Paste, Lacy Baugher Milas stated that "every word of What Moves the Dead feels carefully chosen and deliberately arranged for maximum emotional impact."

Milas praised Kingfisher's characters, particularly noting that "Madeline Usher is granted both the presence and an intriguing level of agency that she doesn't really get much of in Poe's original, and though the end of her story is the same—as it must be—the road to her inevitable death is a much more interesting one.

"[3] Jason Archbold of the Chicago Review of Books wrote that What Moves the Dead transposes the original short story "into the territory of contemporary identity politics and, at the same time, the body horror subgenre."

Archbold praised the expansion of "small cast of somewhat two-dimensional personalities", particularly noting that the "fungal growths which proliferate around the Usher manor perhaps gain the most from Kingfisher's retelling, going from mere description to essentially being a character in their own right".