The mystery is solved! We first noticed it years ago, shortly after moving from Gateshead to Yorkshire – a loud tapping on the roof. As we got to know the house, all those other odd noises that come with unfamiliar buildings revealed themselves. The joists creaking in winter; the plumbing’s rattle; the wind playing in the chimney. Even the scratching just above my pillow on wet nights showed itself to be an ageing rat desperate to gnaw its way into the dry loft. But the roof-tapping resisted detection. Most mornings, at about the time for elevenses, the drumming would begin. With the dumf-dumf-dumf sound, there was often a rolling noise, as though someone were playing marbles. To identify the culprit, I’ve climbed walls and trees, stood on wagon cabs, even asked telephon