Every night, while my husband reads by screen-light, my mind runs like an invisible rat two miles north to the house we’re rebuilding in Islington. And there it scurries from room to room, around the rotten skirting boards, up walls, into corners: testing, considering, fretting. Carpets or wooden boards? Which doorknobs, latches, hinges? Which white for the walls? What will look best, and what (hang your head, o rat) will your friends envy and admire?

Towards 1 a.m.,