It was the first Saturday in August, and the weather in London was warm. Effie and I had known each other for only a few months. We were visiting her brother Stephen, and we had gone out for a walk in the park near his flat. We were lying on our backs on the grass, my head on her lap, enjoying the sunshine and each other's company, relaxing. After we had been chatting desultorily about pretty much everything, the conversa...