A Fickle Friend
It was the end of yet another frustrating session with Dumbledore, who seemed unable to give a straight answer on any topic, no matter how trivial. Harry was reaching the end of his patience.
"But -" he sat perched on the edge of his seat in Dumbledore's office, hands clenched in his lap, and fought for calm and reason.
"Yes, Harry?" The Headmaster looked at him steadily, but Harry thought he heard a trace of impatience.
"I'm sorry, Professor, but I just don't understand," Harry said, frustrated, rubbing his forehead with the heel of his hand. "If it is possible for the prophecy to not come true, then how can it be a prophecy? I thought prophecies had to come true."
"My dear boy," Professor Dumbledore began genially, then stopped. "You are not a student of Arithmancy, are you?"
"Er, no, Professor."
"Oh, excellent," he said warmly. Harry sat back, disconcerted. "You see, Arithmancy is based on the principle that magic conforms to mathematical laws."
"Oh," was all Harry could think of to say. He knew nothing more of Arithmancy than what he had picked up from Hermione, and even less of mathematics.
"Don't worry, Harry, Arithmancy would only hinder your comprehension, as prophecies work on the principle that magic doesn't conform to mathematical limitations." Dumbledore looked at Harry expectantly. Harry tried to think of something clever to say, but all he could think was that he heartily wished he had never raised the subject.
"Er, which is right?" he asked eventually, more as a stalling technique than anything else. He doubted that this was a question that was going to have a hard and fast answer.
"Excellent question, Harry!" Dumbledore beamed at him. It was at times like these that Harry suspected Dumbledore of making fun of him. "It is the second principle that is correct, of course."
"Oh. I mean – of course." Harry was utterly bewildered. "Then why does Arithmancy work?"
"Because wizards believe it does," Dumbledore said simply. There was a long silence. Eventually Harry shook his head slightly, as if brushing that away.
"What does that have to do with prophecies? Professor," he added hastily, wanting an answer, not a lecture on respect. Dumbledore leant back in his tall carven chair and steepled his fingers together in front of him, his eyes more piercing and deep than ever next to the obvious physical frailty of his ruined hand.
"It is quite simple. A prophecy – a true prophecy – tells of what will happen, no matter the odds. Say there was a prophecy that stated that a flipped coin would always come up heads. It is still possible for it to come up tails – there is nothing physically stopping it. It simply won't." He paused for a moment, and looked down over his glasses at Harry. He said quietly, "Mathematics, physics and logic don't apply to magic, Harry. Only will and power. You would do well to remember that."
Many months later, Harry, Ron and Hermione huddled over a small side table in Number 12 Grimmauld Place. Hermione was biting her lip, her brow furrowed with the effort of concentration required.
"All right, Ron. I think it's set," she said tensely.
"This is completely bloody mad, you know," Ron grumbled, but obediently threw the pair of dice. They spun in the air before skittering across the table. All three of them stared at the two sixes.
"Again, Ron," Hermione said, her voice trembling a little. He scooped the dice up with one hand and threw them again.
Harry let out the breath he hadn't realised he was holding with a whoosh, and sat back on his heels. He stared at the dark wall in front of him, unseeing, as Hermione began to babble about probabilities and impossibilities. He thought of Professor Dumbledore, and of power, and of victory.
Thanks, Professor, he thought, and scooped up the dice and put them in his pocket.