“When I was small, I never wanted to step in puddles. Not because of any fear of drowned worms or wet stockings; I was by and large a grubby child, with a blissful disregard for filth of any kind. It was because I couldn’t bring myself to believe that that perfect expanse was no more than a thin film of water over solid earth. I believed it was an opening into some fathomless space. Sometimes, seeing the tiny ripples caused by my approach, I thought the puddle impossibly deep, a bottomless sea in which the lazy coil of tentacle and gleam of scale lay hidden, with the threat of huge bodies and sharp teeth adrift and silent in the far-down depths. And then, looking down into reflection, I would see my own round face and frizzled hair against a featureless blue sweep, and think instead that the puddle was the entrance to another sky. If I stepped in there, I would drop at once, and keep on falling, on and on, into blue space. The only time I would dare to walk through a puddle ...