Albert Johannson lives off the grid. He's forgotten more than he remembers about his past, but those snippets he's retained tell him two things: he's lived a long, looong time and he doesn't trust anyone, particularly gods.
He's not any too fond of demons either, particularly the one that materializes in his kitchen wanting to hire him for a special mission. It's as deadly to cross a demon as to deal with him, so Albert reluctantly agrees to investigate, putting him in the path of a prickly arson detective named Melissa el Hajj with trust issues of her own.
Clashing at a crime scene, they uncover a broken seal that seems ancient enough to have been forged by Solomon himself. The seal cries out to Albert that he must mend it or something dark and dire will happen. Albert, who has a special affinity for metal, must first discover exactly what that will do to his kind - and he's only just beginning to understand who and what he really is.