Nick Tosches feels life ebbing out of him. He wanders New York City's streets and alleys, immersing himself in the crowd, eventually retreating to a dimly lit bar. There, in the gloom, he meets a tantalizing young woman, and the night that follows is unlike anything he has ever experienced. Propelled by uncontrollable, primordial desires, he tastes human blood for the first time and is filled with a sexual and spiritual ecstasy. The revival quickly fades, and soon Nick is yearning for another taste of the elusive rapture. There follows a descent into madness and a darkness beyond any darkness he has ever imagined, culminating in a revelation beyond all darkness and all light as well.