With a skitter of stones, the earth gave way beneath my feet. Landing on my back, I began an inexorable slide downhill towards a tangle of brambles and nettles at the foot of the hill. I travelled several yards down the implausibly steep footpath before I was snagged on a tree root protruding from the slope. Bruised, and a little shaken, I scrambled sidelong to the trunk of the oak that had saved me and sat for a spell while I caught my breath. Far below me, the River Tamar flickered in the autumn sunlight.
