The memory of Slughorn pointedly not telling Tom about Horcruxes finally revealed why Dumbledore had gone through all the trouble of securing the man as their Potions teacher. It was of little surprise to Harry that he was sent to retrieve the "real" memory. Rolling his eyes, as soon as he had closed the door behind himself, Harry strolled to the Potion's Lab to do as he had been told. Predictably the man would not reveal anything. Well, he had promised, and he had tried – nothing to be done about it.