Harry remembered the feeling that a dormant snake had risen in him, ready to strike, in those moments when he and Dumbledore had made eye-contact.
“Voldemort’s aim in possessing you, as he demonstrated tonight, would not have been my destruction. It would have been yours. He hoped, when he possessed you briefly a short while ago, that I would sacrifice you in the hope of killing him. So you see, I have been trying, in distancing myself from you, to protect you, Harry. An old man’s mistake…”
He sighed deeply. Harry was letting the words wash over him. He would have been so interested to know all this a few months ago, but now it was meaningless compared to the gaping chasm inside him that was the loss of Sirius; none of it mattered…
“Sirius told me you felt Voldemort awake inside you the very night that you had the vision of Arthur Weasley’s attack. I knew at once that my worst fears were correct: Voldemort had realised he could use you. In an attempt to arm you against Voldemort’s assaults on your mind, I arranged Occlumency lessons with Professor Snape.”
He paused. Harry watched the sunlight, which was sliding slowly across the polished surface of Dumbledore’s desk, illuminate a silver ink pot and a handsome scarlet quill. Harry could tell that the portraits all around them were awake and listening raptly to Dumbledore’s explanation; he could hear the occasional rustle of robes, the slight clearing of a throat. Phineas Nigellus had still not returned…
“Professor Snape discovered,” Dumbledore resumed, “that you had been dreaming about the door to the Department of Mysteries for months. Voldemort, of course, had been obsessed with the possibility of hearing the prophecy ever since he regained his body; and as he dwelled on the door, so did you, though you did not know what it meant.
“And then you saw Rookwood, who worked in the Department of Mysteries before his arrest, telling Voldemort what we had known all along—that the prophecies held in the Ministry of Magic are heavily protected. Only the people to whom they refer can lift them from the shelves without suffering madness: in this case, either Voldemort himself would have to enter the Ministry of Magic, and risk revealing himself at last—or else you would have to take it for him. It became a matter of even greater urgency that you should master Occlumency—”
“But I didn’t,” muttered Harry. He said it aloud to try and ease the dead weight of guilt inside him: a confession must surely relieve some of the terrible pressure squeezing his heart. “I didn’t practise, I didn’t bother, I could’ve stopped myself having those dreams, Hermione kept telling me to do it, if I had he’d never have been able to show me where to go, and—Sirius wouldn’t—Sirius wouldn’t—”