Amazon.com description: Product Description: Things get a little demonic in the latest Arcane Underwold novel from the author of Splintered.
 
Thanks to their recent involvement with a magus crimelord and his demonic partner in mayhem, occult thieves Anna Ruiz and Karyn Ames are both stuck sharing head space with a demon. But while Karyn’s possession has had the unexpected benefit of focusing her visions of the future, Anna’s demon is spurring on her darkest urges, and it’s only a matter of time before she acts on them—and hurts someone in the process.
 
To save their skins, the two need to find a mysterious relic. But with their search taking them into some of the darkest places in the arcane underworld, Anna and Karyn will have to ally themselves with a group no self-respecting thief would be caught dead with—the Federal Bureau of Investigation...