What Evils Lurk in the Hearts of Men — Mychael Black

Detectives Jonah and Riley Pierce are back in another case for Arcanum, the US government's paranormal police agency. This time, however, they're headed to Berlin when a series of murders points to the enigmatic leader of a research institute. Things turn personal very quickly, though, and they find themselves in a race to stop a psychopathic mortal hellbent on finding the daywalker gene.