"In London, the Metropolitan Police have set up a new Unsolved Murders Unit a cold case squad to catch the criminals nobody else can. Four victims. Four cases. All killers poised to strike again. Only Warwick's genius for deductive reasoning, his fierce intelligence and his occasionally rash bravery combined with that of ex-undercover operative Ross Hogan, reluctantly brought in from the cold can bring the criminals to justice, and put his nemesis behind bars."