I watched Amber, the crime drama created by RTE in Ireland and shown recently on BBC Four, entirely on BBC iPlayer, anxiously avoiding spoilers because I was determined not to find out what happened to the 14-year-old who went missing in episode one.

I had a particular interest in this one because it occurred to me that the storyline was along the lines of the plot I’m writing about in my next book, Behind Closed Doors (which will be coming out in paperback next year). I’m always anxious about...