When Eric Ward and Sharon Owen defend suspected serial killer Raymond Conroy, they win an acquittal on a technicality thus incurring the wrath of CI Charlie Spate. Ward has no desire to act further for Conroy when the man decides to remain in the north east. Instead he concentrates on issues arising from Sharon's family trust, though harassed by a journalist who seeks to interview Conroy. But when Conroy disappears, and the Zodiac Killer strikes again, this time on Tyneside, Ward finds himself involved once more, alongside CI Spate who is under pressure for his apparent incompetence in tracking Conroy. Complications arise from mysterious dealings in Scotland in the seventies, but it is only during a murderous climax in a remote Northumberland farmhouse that the truth finally emerges in the hunt for the Zodiac Killer.