It was the third Friday in September. The late afternoon sun was fading, and dusk was coming on fast. Unlike those who talked about how much they loved fall, Winston found all this a depressing prelude to an even more depressing winter season.

He had just taken his recycling out to the curb when he noticed a smallish light approaching. In a moment or two, he saw that it was someone on a bicycle, and then as they got closer, he saw it was a woman.

"Professor Fletcher?" The bicycle stopped, and the woman got off. He couldn't quite make out who she was, but even in the fading light,...