Ghost in the Serpent — Jonathan Moeller

A deadly poison. A hidden cult of sorcerers. Only Caina can find the truth.Caina is a Countess of the Empire, an advisor and friend to three powerful monarchs.But she was once a nightfighter of the Ghosts, the spies and assassins of the Emperor, and faced lethal sorcerers and corrupt lords. And when a hidden cult of malevolent sorcerers emerges from the shadows, Caina will show them that she has forgotten none of her old skills...