Jesse Madding has been working for Gideon, a vampire fighting to maintain the balance between good and evil, for two years, and has loved him for nearly that long. When Gideon slams him against an alley wall and demands sex, Jesse is too happy to oblige, but it opens doors in their relationship that Gideon isn't sure he wants to enter. Especially since he suspects he was under the powerful influence of an unknown substance, and Jesse is his best friend. As they try to negotiate a new relationship involving Jesse's willing submission to Gideon's darker desires--including bondage, pain, and bloodplay--they learn that a new drug is being distributed in the city. Known simply as "obsidian," this drug unleashes a vampire's demon, destroying any sense of self-control. Widespread use of obsidian could bring chaos to Chicago and turn the city into a bloodbath, but even as Jesse and Gideon race to contain it, they're consumed and distracted by their own growing passion and burgeoning emotions...