The world is ruled by blood purity. Angels sit on the tops of the skyscrapers sprawled across the planet, while demons populate the poverty-stricken undercity. 

Nivena is an Asuri with nineteen counts of homicide to her name. Ciardah is a half-demon, half-human hybrid and a notorious thief.  And they only have one thing in common. The Book of Red, a knife that has become the most dangerous weapon in history, and never hurts anyone it touches.

Someone else wants the Book. And they'll do anything to get it.