His voice was carefully controlled, but Harry could sense his excitement.
“Well, you split your soul, you see,” said Slughorn, “and hide part of it in an object outside the body. Then, even if one’s body is attacked or destroyed, one cannot die, for part of the soul remains earthbound and undamaged. But of course, existence in such a form . . .”
Slughorn’s face crumpled and Harry found himself remembering words he had heard nearly two years before: “I was ripped from my body, I was less than spirit, less than the meanest ghost . . . but still, I was alive.”
“. . . few would want it, Tom, very few. Death would be preferable.”
But Riddle’s hunger was now apparent; his expression was greedy, he could no longer hide his longing.
“How do you split your soul?”
“Well,” said Slughorn uncomfortably, “you must understand that the soul is supposed to remain intact and whole. Splitting it is an act of violation, it is against nature.”
“But how do you do it?”
“By an act of evil — the supreme act of evil. By committing murder. Killing rips the soul apart. The wizard intent upon creating a Horcrux would use the damage to his advantage: He would encase the torn portion —”
“Encase? But how — ?”
“There is a spell, do not ask me, I don’t know!” said Slughorn, shaking his head like an old elephant bothered by mosquitoes. “Do I look as though I have tried it — do I look like a killer?”
“No, sir, of course not,” said Riddle quickly. “I’m sorry . . . I didn’t mean to offend . . .”
“Not at all, not at all, not offended,” said Slughorn gruffly. “It’s natural to feel some curiosity about these things. . . . Wizards of a certain caliber have always been drawn to that aspect of magic. . . .”
“Yes, sir,” said Riddle. “What I don’t understand, though — just out of curiosity — I mean, would one Horcrux be much use? Can you only split your soul once? Wouldn’t it be better, make you stronger, to have your soul in more pieces, I mean, for instance, isn’t seven the most powerfully magical number, wouldn’t seven — ?”
“Merlin’s beard, Tom!” yelped Slughorn. “Seven! Isn’t it bad enough to think of killing one person? And in any case . . . bad enough to divide the soul . . . but to rip it into seven pieces . . .”
Slughorn looked deeply troubled now: He was gazing at Riddle as though he had never seen him plainly before, and Harry could tell that he was regretting entering into the conversation at all.
“Of course,” he muttered, “this is all hypothetical, what we’re discussing, isn’t it? All academic . . .”
“Yes, sir, of course,” said Riddle quickly.
“But all the same, Tom . . . keep it quiet, what I’ve told — that’s to say, what we’ve discussed. People wouldn’t like to think we’ve been chatting about Horcruxes. It’s a banned subject at Hogwarts, you know. . . . Dumbledore’s particularly fierce about it. . . .”
“I won’t say a word, sir,” said Riddle, and he left, but not before Harry had glimpsed his face, which was full of that same wild happiness it had worn when he had first found out that he was a wizard, the sort of happiness that did not enhance his handsome features, but made them, somehow, less human. . . .
“Thank you, Harry,” said Dumbledore quietly. “Let us go. . . .”
When Harry landed back on the office floor Dumbledore was already sitting down behind his desk. Harry sat too and waited for Dumbledore to speak.
“I have been hoping for this piece of evidence for a very long time,” said Dumbledore at last. “It confirms the theory on which I have been working, it tells me that I am right, and also how very far there is still to go. . . .”
Harry suddenly noticed that every single one of the old headmasters and headmistresses in the portraits around the walls was awake and listening in on their conversation. A corpulent, red-nosed wizard had actually taken out an ear trumpet.
“Well, Harry,” said Dumbledore, “I am sure you understood the significance of what we just heard. At the same age as you are now, give or take a few months, Tom Riddle was doing all he could to find out how to make himself immortal.”
“You think he succeeded then, sir?” asked Harry. “He made a Horcrux? And that’s why he didn’t die when he attacked me? He had a Horcrux hidden somewhere? A bit of his soul was safe?”
“A bit . . . or more,” said Dumbledore. “You heard Voldemort: What he particularly wanted from Horace was an opinion on what would happen to the wizard who created more than one Horcrux, what would happen to the wizard so determined to evade death that he would be prepared to murder many times, rip his soul repeatedly, so as to store it in many, separately concealed Horcruxes. No book would have given him that information. As far as I know — as far, I am sure, as Voldemort knew — no wizard had ever done more than tear his soul in two.”
Dumbledore paused for a moment, marshaling his thoughts, and then said, “Four years ago, I received what I considered certain proof that Voldemort had split his soul.”
“Where?” asked Harry. “How?”
“You handed it to me, Harry,” said Dumbledore. “The diary, Riddle’s diary, the one giving instructions on how to reopen the Chamber of Secrets.”
“I don’t understand, sir,” said Harry.
“Well, although I did not see the Riddle who came out of the diary, what you described to me was a phenomenon I had never witnessed. A mere memory starting to act and think for itself? A mere memory, sapping the life out of the girl into whose hands it had fallen? No, something much more sinister had lived inside that book . . . a fragment of soul, I was almost sure of it. The diary had been a Horcrux. But this raised as many questions as it answered.
“What intrigued and alarmed me most was that that diary had been intended as a weapon as much as a safeguard.”