Not long ago I sat up till 3 am reading a book on my computer screen. I had not planned to do this; I thought I had ordered a print copy then found I had been sent an ‘e-book’ instead – and I don’t have a kindle. It was simply too exciting to stop so I scrolled down and down until I reached the end. Was this pious Lenten reading? Er – no. It was The Spy and the Traitor by Ben Macintyre, published last autumn and recommended to me by a friend who knows two of the principal players in the story.