Luc and Shiloh Bishop have everything they want. The only problem being... they still owe Lucifer a favor. When Lucifer shows up again, he decides to call in his debt. A Fallen angel has gone rogue, and is cutting a path of death through Lucifer's demons. With the help of another Fallen, the Bishops have to stop Abaddon, before he reveals demons to the world. If Abaddon cannot be defeated, then the Bishops debt just may get paid in blood.