Nocturnal - Scott Sigler

For centuries, their race has lived beneath the earth, emerging only at night, to feed quietly on the dregs of society and slip back into the shadows. But now their time has come - their time to rise up from their hiding places and take back what is theirs.

San Francisco homicide detective Bryan Klauser is supposed to be hunting a serial killer. But a serial killer couldn't be responsible for the seemingly impossible DNA evidence the crime-scene techs keep finding - or for the gory, strangely prophetic dreams Bryan keeps having. And what about the connections he keeps finding to a century-old cult - and his superiors' sudden reluctance to give him the answers
he needs about cases that should be dead and buried?

Ultimately, Klauser's investigations will reveal a race of killers who've long lurked beneath San Francisco's streets - and are preparing to take back the city. Klauser is the only man who can stop them, because . . . he might not be a man at
all.