In order to destroy a legendary monster and save the royal family, Kelsey must make a deal with a devil.

When Kelsey Owens returns home to Dallas, she is a changed woman. After months of training with Marcus Vorenus, she has more control over her abilities. She’s ready to start her new job, even if it means dealing with the King of All Vampires and his partner, Devinshea Quinn. Her first assignment, however, will force her to face her past. Grayson Sloane is in trouble and she has to find him.

With the help of Gray’s brother, a full empath demon, Kelsey tracks her one-time lover down. Before she knows it, she’s pulled into Gray’s undercover operation in a demon sex club and sitting across from a Duke of Hell. Abbas Hiberna plans to use her city to test his new drug, Brimstone. It doesn’t just give supernatural creatures a high. It also leaves them vulnerable to demonic persuasion.

When the king’s own men begin to turn against him, even the royal family is in danger. Keeping them safe will put Kelsey in the duke’s crosshairs and test her fledgling relationship with Marcus. With her new life crumbling around her, a dark secret about her former lover is revealed, and Kelsey will have to choose between saving Gray Sloane and the revenge she’s waited a lifetime for.