I had agreed to look after my younger cousin for an hour. I wrote the emergency numbers on a card and asked what time he usually went to bed. When his parents closed the front door, the house seemed much quieter than it had a moment earlier. I wanted them to trust me, but I also wished they had repeated the instructions. For the first few minutes, I watched the clock and listened whenever the floorboards creaked upstairs. Then my cousin called down to ask whether we could finish the puzzle we had started. His ordinary voice made me smile, and I went upstairs without looking at the card.