Halfway across the first floor, heading for the staircase, Percy ran into Professor McGonagall, who was dragging Draco Malfoy by the ear. "Oh," he said in complete surprise, his voice squeaking slightly with nerves, "hello, Professor." McGonagall wasn't usually awake at this hour; night patrol duty fell to the prefects, and they reported to Sinistra rather than to their Heads of House, since the Astronomy professor was always up at night. Usually no one woke up any of the other professors unless something came up that required further authority.