A decade ago, psychologist Frieda Klein was sucked into the orbit of Dean Reeve -- a killer able to impersonate almost anyone, a man who can disappear without a trace, a psychopath obsessed with Frieda herself. In the years since, Frieda has worked with -- and sometimes against -- the London police in solving their most baffling cases. But now she's in hiding, driven to isolation by Reeve. When a series of murders announces his return, Frieda must emerge from the shadows to confront her nemesis. And it's a showdown she might not survive. Criminology student Lola Hayes has tracked Frieda down with a single-minded pursuit: she wants to delve inside the mind of a woman besieged by darkness. But in following every move Frieda makes, Lola is exposing herself to the same terrors--and the same twisted fixation of a diabolical psychopath.