He meets women. He gains their trust. He kills them. That's all London police detective Maeve Kerrigan knows about the man she is hunting. Three women have been strangled in their homes, but the victims' neighbors and friends don't remember anything unusual or suspicious. Maeve is almost at a loss about how to move forward. Then the evidence starts to point to a shocking suspect: DCI Josh Derwent, Maeve's partner on the police force.