The criminals in a northern English city are asking for it. A feeble law enforcement establishment is being run ragged. The family of a hospital pathologist, Jack Preston, is killed by a drunken criminal driving the wrong way up a motorway exit. The culprit, Darren Darnell, receives a derisory sentence because the trial judge makes an excuse for him Hard line Detective Hugh Mason, whose own career is on the skids, senses that Jack Preston isn't the usual grieving victim. He manipulates Preston who kills Darnell in a totally unexpected way. Mason's career then takes an upward path but so does Preston's. Previously content with domestic obscurity, he wins a professorship in charge of a modern 'profit generating' path lab at the local university. This leads him to the Old Bailey where he proves the guilt of a policeman, Morton Horder, in a high profile murder case. The guilty copper's defence counsel, Rose Elstein, a Liberal Democrat candidate, latches onto Jack. Mason is far from happy that Preston has helped to convict a fellow policeman. He wrongly believes Jack is a master of secret methods of poisoning. Mason goes on to blackmail Jack into 'removing' a succession of serial killers and paedophiles . . . To save his ongoing romance with Rose Jack is driven to helping Mason. A killer George Bosniak is removed. A blackmailer finds himself choking, is saved by Preston but loses his blackmail material. Jeff Dibutt, head of a paedophile ring is forced to disclose where his latest still living victim is hidden. Finally, Jack's greatest struggle is against former Iraq War soldier Dieter Jenkinson who covets Jack's friendship with Rose and plots to kill her.