A lost grimoire. A dangerous new enemy. And a powerful magical weapon that could destroy the world.

When Jayne Thorne's CIA mentor goes missing on a top-secret mission, she is sent to Paris to find him, only to land in the crosshairs of a deadly terrorist organization and their diabolical weapon, a mysterious poison that renders magicians powerless.

Fighting to combat this new enemy, Jayne also struggles to make peace with her sister, who has been hiding the truth of their family history for years, and overcome difficulties with Cillian, whose Rogue magic can't quite sync up with Jayne's otherworldly powers. Even worse, her enemies demand she locate a necromantic grimoire in France, or they will kill her mentor.

As Jayne hunts for the grimoire, she unlocks the secret to summoning the Master of Shadows—a long-dead master magician possessing a dark and destructive magic. With this lethal power unleashed, she must protect her team from the worst magical threats they've ever faced...or suffer the deadly consequences.

"Everything I love about urban fantasy." –John McDougall, Murder by the Book