This is a city unlike any other, one half held in perpetual daylight, the other in permanent darkness. Below the neon skies of Dayzone, where the lights never go out, and night has been banished, lowly private eye John Nyquist takes on a teenage runaway case. His quest takes him from Dayzone into the blackness of the city's other side, Nocturna. As a vicious, seemingly invisible serial killer the press have nicknamed Quicksilver haunts the streets, Nyquist starts to suspect that the runaway girl holds within her the key to the city's fate. In the end, there's only one place left to search: the shadow-choked zone known as Dusk.