"There are days when I teach writing at 4.00. It's the time the Scots call the "gloaming," no longer daylight, but not yet night. Still too early to light a fire. Usually a student turns on the classroom lights, but on some days the first six or seven students just come in and sit in the growing darkness, exhausted; they don't talk. I come in the room, turn on the lights, and feel as if there is a great weight that I must move, and I'm not always sure I can do it."