Synopsis: Steam on the Line (Historical Cycle) The Industrial Revolution comes to Darnley Mills and the countryside around it. A whole way of life must change and Philip Turner uses the story of young Taffy Hughes and Sarah Thurgood to reflect just what happens. The Devils' Back and Darnley Mills Light Railway is at the centre of the change and at the heart of the story. Life is full of hard work, excitement, challenge and danger. Both Sarah and Taffy find themselves more deeply involved than they ever intended.