If only Granger would show up after her last lesson that day, or he would have to go find her and orchestrate an argument to get her all flustered. That didn't sound like a bad idea, and he was just about halfway across the room when the portrait swung open and he could hear the brazen voice of the stupid knight, who from the sounds of it had fallen off his fat pony again. He had his wand out in the flash of barely a second it took for her to enter and close the portrait behind her. In that second he had charmed the entrance locked and cast a Silencing Spell on the entire room for any potential nosy ears outside.