D.I. Graves is back on the case to face his toughest challenge yet: a case with no motive and no suspect, nothing at all that could explain why someone would kill innocent people and then take parts from the bodies. Then the next victims are discovered: another pair of bodies, new body parts taken, and again in their own home. Someone is breaking into houses across the city at night, leaving horror in their wake. It seems to Graves that this could be two serial killers, working together. But how are they choosing their victims? Is any house in London a target? Is anyone safe? To make matters worse, a journalist is threatening to cause more harm than good with her obsessive push in covering the story to further her career, and someone is targeting Graves personally, seeking revenge against him in relation to an old case. Can Graves keep himself safe long enough to stop the serial killers before they strike again?