Vampire attacks are on the rise after nearly seventy years of peaceful coexistence with hybrids and humans. A rogue vampire is targeting young women and leaving a trail of bodies in his wake. The Alliance, a police force comprised of hybrids, vampires, and human warriors, is on a mission to stop him.
 
Sofia Pierce, a feisty human doctor, crosses paths with Gage Gallegos, a lethal vampire-hybrid known as Lucifer from The Alliance. Drawn to each other instantly, Sofia accepts a job as The Alliance's resident doctor, eager for a challenge and to delve into hybrid and vampire biology.
 
As the rogue vampire grows bolder, ordering the massacre of nearly thirty women, The Alliance realizes Sofia is in grave danger. The killer has been tracking Gage for over 150 years, and now it seems Sofia is his ultimate target. Under constant protection, Sofia forms unbreakable bonds with some of the toughest warriors on the planet.
 
But the reasons behind the killer's obsession with Gage—and his interest in Sofia—are more disturbing than they could ever imagine. As Sofia and Gage uncover dark secrets about their pasts, they must decide whether these revelations will tear them apart or bind them forever.
 
In a world unraveling around them, Sofia and Gage must face a deadly threat, fighting for their lives and their love.