Detective Renée Ballard works the graveyard shift and returns to Hollywood Station in the early hours to find a stranger rifling through old files. The intruder is none other than legendary LAPD detective Harry Bosch, hunting for leads in an unsolved case that has got under his skin. Ballard escorts him out but - curious to know what he was searching for - soon becomes obsessed by the murder of Daisy Clayton. Was she the first victim of a serial killer who still stalks the streets? For Bosch, the case is more than personal: it may be all he has left. But in a city where crime never sleeps, even detectives have a dark side.