The Kill : (Maeve Kerrigan 5)

Their job is to investigate crime - not become the victims... 

A killer is terrorising London but this time the police are the targets. Urgently re-assigned to investigate a series of brutal attacks on fellow officers, Maeve Kerrigan and her boss Josh Derwent have little idea what motivates the killer's fury against the force. 

But they know it will only be a matter of time before the killer strikes again.