After a day of bright light falling through diaphanous patches of cirrus clouds, the sun at last vanished into a dark bank of clouds that covered the valley. All there was of sunset was a pale band of purple above the dark mass, and a glow of pale rose in the thin clouds directly overhead as they were struck from the bottom by the vanishing light. Then, the fog rolled over the ridge until full darkness, when it thinned and revealed a cold night of stars.