Private investigator Mason Gray has a reputation for solving impossible cases. But when an ancient artifact inexplicably vanishes from the Field Museum, that reputation will be put to the test.
To solve this case, he must delve deeper into Chicago's supernatural world and call on his newly discovered abilities - unless they kill him in the process - to find a thief who's never been caught.
But things are never as they appear in the White City, and every answer he uncovers leads to new questions. And new enemies.
If Gray fails to recover the artifact, it will start a war that will destroy the city he loves. To save it, he is forced to make an impossible choice: make a deal with the devil or become one himself.