the first snowfall in chicago followed the first 20 degree night, so that sunday, walking down a quiet, tree-lined residential street, the snowflakes were bumping elbows with the leaves, which were dropping off the trees seemingly of their own accord: no wind to shake them loose, just an imperceptible snap, fibers weakened by the cold night, and they drifted toward the street, mingling with the fat, dry snowflakes.