Retribution is the only option when justice turns a blind eye. Returning from three months compassionate leave following the death of his wife, DCI Mike Pullman is thrown into investigating a series of gruesome murders. A decapitated corpse is discovered on the promenade of an East Yorkshire coastal town; the victim's head is found forty miles away with a message scrawled on the forehead. This murder, initially considered to be local starts Pullman on an investigation that finds him seconded to the National Crime Agency in London to lead the investigation into this and further murders in Glasgow and London linked to a series of gruesome killings across the world, over a five year period.