My mother would read the first two chapters of my next book as I wrote them. She then wrote down the name of the murderer and put it in a sealed envelope. We opened this together when I had finished the book. She was never wrong. I hadn’t meant to live with mother—it was a case of force majeure. I had had every intention of leaving home at the age of eighteen—the earliest possible opportunity for me to do so in those days—and following in my father’s footsteps to Edinburgh University. I was going to read medicine there on the way to becoming either a general medical practitioner or a physician—surgery never having appealed to me. To this end I was in the Lower Sixth form at school studying chemistry, physics and biology, as well as learning Latin as a subsidiary side-dish.