One day later, still in Dumbledore's Headmaster's Office.
This time, however, the person sitting before Dumbledore was a handsome middle-aged man with black hair. He wore elegant, carefully tailored clothes that nevertheless seemed a little too old-fashioned, giving him the air of an old pure-blood aristocrat. At the moment, he was gripping a piece of parchment, his eyes fixed motionlessly on the writing upon it. His tightly pressed lips and slightly whitened knuckles showed clearly that his emotions were far from calm...
It was Sirius Black.
Originally, he had been dealing with the aftermath of the werewolf attacks, secretly cooperating with the Order of the Phoenix and the Aurors to capture Greyback's fleeing subordinates. But after receiving Dumbledore's urgent letter last night, he had immediately rushed back to Hogwarts.
"What are you thinking, Sirius?"
Seeing that the man before him had remained silent for so long, Dumbledore had no choice but to be the first to pull him back from his tumultuous thoughts, prompting him to look up again.
"You..."
Sirius Black had only managed to utter a single word before realizing, in surprise, that his voice was frighteningly hoarse. He quickly swallowed before forcing it back into something listenable.
"I think your guess is right. It absolutely was Regulus Black, my brother..."
"You may not know this, but there had long been rumors within our family that he did not die at the hands of the Aurors, but was killed by Voldemort or one of Voldemort's followers... From what I learned after his death, he had already sunk in very deep, and then he became afraid of what people were asking him to do, so he wanted out. And as you know, he couldn't exactly hand Voldemort a resignation letter and be done with it. Either you serve for life, or you die."
"But I never imagined... never imagined... he would be so..."
"Brave."
Dumbledore supplied the word for the somewhat incoherent Sirius and handed him a cup of tea.
"Thank you."
With none of an aristocrat's refinement, Sirius tilted his head back and drained the tea in one gulp, his voice thick with emotion.
"At the time, he was the one who admired Voldemort the most... I always thought he was a stupid fool..."
"Professor, according to what you said, drinking that potion would make a person unbearably thirsty, and they would instinctively drink the lake water and then get dragged down by the Inferi... Then he's very likely still at the bottom of that lake, isn't he?"
"Either him, or his companion."
Dumbledore did not commit himself either way.
"And to say something rather unpleasant—him being in the lake would actually be the best-case scenario. That would mean he chose to drink the potion himself and let his companion escape with the real Horcrux in secret. But on the other hand, if it was his companion lying in that lake instead... you said it yourself, according to your family's information, Regulus died at Voldemort's hands, correct?"
"That would mean all his efforts were in vain. Voldemort got the Horcrux back from him and hid it away once more, and before dying, he would certainly have suffered unimaginable torment."
Dumbledore could not help but feel a little pained.
As he said those words, Sirius's breathing had almost stopped.
"I... I want to go see."
After who knew how long of silence, Sirius finally let out a low plea.
"Can I, Professor? I'll recognize him if he's really there..."
"...All right."
That would mean breaking the magic Voldemort had cast over the lake, then dragging every Inferius out of the water and identifying them one by one. It would disrupt Dumbledore's original plans somewhat.
But looking at Sirius as he was now, Dumbledore could not think of any way to bring himself to say no.
...
With a flash of fire, Sirius and Dumbledore appeared once again on the island in the middle of the Horcrux cave's lake.
"A quick solution might cause a bit of damage... ah well, it's not as if this place will be needed anymore."
Dumbledore muttered that with a somewhat self-mocking tone.
His students were always capable of bringing him unexpected surprises.
While muttering, he drew out the Elder Wand again and made several grand sweeping motions toward the lake. Under his movements, the once-still lake first rippled slightly, then quickly grew into waves, and then into a raging whirlpool...
In only a few moments, the entire lake—reinforced by Voldemort's magic—had begun to boil under the power of his wand, and the Inferi hidden within it could do nothing but rise and fall helplessly with the surging waters.
At last, from what seemed to be the deepest part of the lake, there came a sharp crack, as though something had snapped.
With that sound, all the water in the lake seemed to break free of some invisible restraint, becoming visibly more active. If Dumbledore's previous attempt to force the lake into motion had been like laboriously stirring cement, then now it had become nothing more than an ordinary pond, one that anyone could easily send into waves.
"Fortunately, that was easier than expected. Sirius, get ready."
Dumbledore turned to remind the dazed Sirius at his side, then lightly raised his wand, lifting all the water of the lake—along with every Inferius inside it—into the air. The water then condensed into chains, tightly binding each Inferius in place, before carrying them out of the lake and arranging them in neat rows before Sirius.
Sirius had no time to be astonished by Dumbledore's power. He stared wide-eyed as he carefully examined the face of every single Inferius...
Fortunately, corpses turned into Inferi became much sturdier and harder to decay. So even after soaking underwater for more than ten years, their features were still clearly recognizable.
"It's him!"
Suddenly, he pointed at one of the Inferi and cried out in a trembling voice.
"It's him, not anyone else, it's him..."
Though Sirius was nearly incoherent at this point, Dumbledore still understood what he meant. He guided the Inferius Sirius had pointed out down slowly, lowering it to the ground before him.
That Inferius struggled frantically, trying to attack the "enemy" before it, but Dumbledore's water chains held it fast.
Dumbledore frowned, tapped Regulus's body with his wand, and immediately thick, gloomy black mist began to pour from his mouth and nose. His bluish, deathly skin gradually returned to a natural color as well...
A moment later, what lay before Sirius was a body in soaked robes, looking as though it were merely asleep.
"...Thank you."
Sirius knelt on one knee, clutching Regulus's hand tightly, his shoulders trembling in silent sobs. After offering Dumbledore a brief word of thanks, the cave fell into a long silence...
"I'm sorry, Professor."
Only after an unknown span of time did he stand back up, looking at Dumbledore, who had been quietly waiting nearby, with reddened eyes.
"I lost control of myself a little. I'm sorry..."
"And perhaps I already know who Regulus's companion was... Kreacher. It could only have been Kreacher."
"Only a house-elf who obeyed his every order completely could have been trusted by him in something this important, entrusted to safeguard the real Horcrux in his place... He's at Grimmauld Place right now!"
"We need to find him!"
(End of Chapter)