George looked up from where he was examining a wall sconce under wandlight. "Somebody awake?" he inquired curiously. It was past midnight, and Fred's keeping an eye on the Map in case of interruption was mostly a useful habit. They hadn't been expecting to run into anyone; Filch was out on the grounds delivering Ron and Malfoy to detention with Hagrid (maybe Ron wasn't a lost cause after all), and periodically checking the seventh floor showed that Mrs. Norris was skulking around Ravenclaw Tower. The Map didn't show everything all at the same time, but it showed you whatever you thought was important, which was just as good if you had a good sense of priorities.