Gideon the Ninth Novel by Tamsyn Muir

Gideon the Ninth by Tamsyn Muir is the first novel in The Locked Tomb series, a critically acclaimed science fantasy novel praised for its unique blend of gothic horror, sharp humor, and a central murder mystery. The story follows the sarcastic swordswoman Gideon Nav, who is forced to become the cavalier to her nemesis, the powerful necromancer Harrowhark Nonagesimus.