When the murdered body of a woman is found in a Sheffield carpark, former cop turned private investigator Matt Forrester finds himself embroiled in the case, because the last call the victim made was to him... But the case isn't as simple as the drug theft it looks like, and - when a young boy becomes the next victim - Matt and his life partner, DI Karen Nelson, realise they're investigating a terrifying series of revenge killings. Arrests start to be made, but enemies are being made. And, as the killings continue, nobody is safe...