"At Hogwarts, he’s in enemy territory. He’s separated from his Death Eaters - there’s no way he’ll bring them with him," Harry said with a scoff, "He doesn’t want  anyone to know about his Horcruxes after all. So, he’s away from his headquarters, he’s cut off from his allies, he’s surrounded by enemies on all sides," with each declaration, Harry counted along his fingers, "and he’s trapped in a building he can’t easily leave if he needs to flee - you can’t apparate out of Hogwarts after all.