1984: It looked like a simple job. That was why they gave it to him. Guarding a woman nameless and almost faceless after a savage acid attack – at a Glasgow hospital, PC Alan McAlpine has no idea that this simple job will haunt his career and change his life forever.2006: Two decades later, Alan steps into Partickhill police station and back in time. Now a celebrated Detective Chief Inspector, McAlpine has been drafted in to lead the hunt for a man the press are calling 'the Crucifixion Killer'. Two women are already dead, their mutilated bodies laid with arms outstretched.With his distinguished reputation, McAlpine's team are confident their new DCI will lead them to the killer. But the obsession that was born in a hospital room twenty-two years earlier has never quite left Alan. And now, it seems, its come back for a reason.