On a cold morning at the end of January I am driving to a small town twenty miles away to visit one of my home-healthcare clients. We’ll call her M. She is eighty-nine, has one daughter who rarely visits, and is fairly healthy aside from a diagnosis of mild senile dementia. Her old New Hampshire farmhouse is at the top of a snowy hill and has drafty doors and uneven floors. M. and I have agreed that I will come at eleven on the days that I help her, but she rises late and is never ready. She can’t seem to grasp that I have a limited amount of time to spend with her.