Four cases. Four killers. Only one man can stop them ... In London: The Metropolitan Police set up a cold case squad to catch the criminals nobody else can. In Geneva: Millionaire art collector Miles Faulkner was pronounced dead two months ago. So why is his unscrupulous lawyer still representing a dead client? On a luxury liner en route to New York: The battle for power within a wealthy dynasty is about to turn to murder. And at the heart of each investigation is Detective Chief Inspector William Warwick, together with ex-undercover operative Ross Hogan, brought in from the cold. But can they catch the killers before it's too late?