Until the summer my grandmother was dying, my children were the only people I had ever watched sleep. I used to lie beside them at nap time, taking shallow breaths, while I waited for a thumb to fall away from a mouth or for a jaw to drop open: the signal that they had drifted off. I willed them unconscious with all the silent concentration that a white-knuckled passenger in the back row uses to fly a jetliner. Sounds from outside the room seemed magnified then; a distant door slamming or a slightly raised voice threatened to wake them. In the presence of my sleeping grandmother it was altogether different. Even nearby noises—a car starting in the lot outside her window, the phone ringing—seemed curiously muffled. A neighbor down the hall conducted mysterious business in his home office, but his voice sounded as if it were coming from far away. I adjusted the fan toward her bed and covered her legs with the sheet. I watched my grandmother’s breath enter and leave her body and willed it, not to steady into the even metronome that accompanied my children’s dreams, but to stop. …