Master of Shadows - Jayne Thorne, CIA Librarian, #2

In a world on the brink of chaos, CIA agent Jayne Thorne faces her deadliest mission yet. A ruthless cabal of dark sorcerers, hell-bent on unleashing chaos and destruction upon the world, seeks a long-lost grimoire to unleash a catastrophic magical weapon. With her mentor missing and time running out, Jayne must navigate a treacherous web of secrets and lies to uncover the truth before it's too late.
As Jayne races against the clock, she finds herself in the heart of Paris, battling a terrifying poison that renders even the most powerful magicians helpless. Haunted by shocking revelations about her family's hidden past and strained by her increasingly volatile relationship with Cillian, whose Rogue magic clashes with her own otherworldly powers, Jayne is pushed to her limits. But the stakes have never been higher.
Jayne's enemies demand she locate the ancient necromantic grimoire, threatening to execute her mentor if she fails. Desperate and running out of options, Jayne must unlock a forbidden power that could resurrect the Master of Shadows-a long-dead sorcerer wielding devastating dark magic. With the fate of the world hanging in the balance, Jayne must confront unimaginable threats, protect her team from the deadliest magical forces she's ever encountered, and make an impossible choice that will determine the destiny of humanity itself.
In this thrilling tale of sacrifice, secrets, and the ultimate battle between light and darkness, Jayne Thorne must risk everything to save the world from plunging into eternal shadow. This award winning contemporary fantasy, set in a unique magical world, is perfect for fans of Leigh Bardugo, Linsey Hall, Ilona Andrews, and Patricia Briggs! "Everything I love about urban fantasy." -John McDougall, Murder by the Book