In a city full of mysteries, Queen Mab, the forces of light and darkness clash in a deadly battle for the truth. Dedicated agents of the Sacred Inquisition hunt a long-time enemy— the infamous Cognite society—trying to uncover the secret of the identity of the all-powerful King-in-Yellow. At the center of this war is the outcast Elizabeth Bickwin. Whose side will she take: the Inquisition, or Cognite—the ones who raised her? And if she chooses the Inquisition, who will become her ally: the wise but merciless Ravenor, or Eisenhorn, declared a heretic? To solve the most important secret for her, Bickwin will have to fight angels, demons, and even monstrous warriors from the Treacherous Legions. Loved by readers, Eisenhorn and Ravenor return as unyielding rivals. The novel is packed with mystical secrets, grim intrigues, and vivid scenes. Calling things by their proper names may mean destroying yourself… or shaking the Imperium to its very foundations.