Resurgence - Evans S. Usher

Jack Grenard's life changed three years ago when his wife was brutally murdered by the very demons he'd been hunting. At the urging of his partner Cam Macarro, he's starting a new life in Atlanta, hoping he'll find the man he used to be. But on a routine hunt, they come across a new type of demon—one that saves instead of kills.

Meanwhile, demons across Atlanta are preparing for the quadrennial uprising of their Underground brethren. Worse yet, there's a rumor the so-called King of the Demons, Bael, will appear. Jack and Cam must uncover the truth about the mystery woman before all hell—literally—breaks loose. 

Resurgence is the latest book from S. Usher Evans, author of the Madion War Trilogy, Razia series, Lexie Carrigan Chronicles, and Empath.