North of Westbury the land finally lifts — the old moraine ridge the ice left behind when it stopped — and winter weather comes over it and settles onto the flat below. Summit Snow Removal works that flat at dusk and after, when the light turns blue and the thermometer drops through the point where wet becomes ice. Plowing driveways and parking areas, shoveling steps and walkways, laying salt and sand on the spots that glaze first. When a storm runs long the crew comes back rather than waiting it out. The measure of the night is simple: black pavement, and a walkway you can cross in the dark.