In the back of the old clay lump farm cottage in Norfolk, the barn door still stuck in damp weather, just as it always had. I leaned my shoulder into it until it gave with a sigh of swollen wood and rusted hinges. Inside hung the tools of three generations: ash-handled spades blackened with age, a Dutch hoe with its blade worn thin as paper, and my Great-grandfather’s fork, one tine bent slightly inward after striking buried stone sometime before the first war. I lifted the f