I stepped out the back door under a blue sky. By the time I had got down the lane, the sun had disappeared under a skirl of dirty clouds. The clouds sketched themselves thicker and thicker so that as I neared the lone oak, the afternoon had turned dark. Then it began to rain. Slanting in from the north-west, the teeming drops were cold and squally. I only just made it to the sheltering tree in time. After 10 minutes the downpour slackened.