That was the miracle, plain and enormous: my son ran.

He tore across the green lawn behind the house chasing a golden retriever we had taken in, a big goofy golden retriever named Barnaby who adored him from the first day, and he laughed while he ran, and his cheeks were flushed a deep and healthy color, and his chest rose and fell with easy, effortless breath.

I would stand at the window with a dish towel in my hands and simply watch him, this boy who a year before could not climb a flight of stairs without stopping to gasp, now flying across the grass as though he had never known a sick day in his life.

There is no wealth on earth, I learned, to match the sight of a child you nearly lost, running in the sun.