Tom brought the automated retrieval to a halt and conjured a light, flooding the cave with enough brightness to see clearly.
He looked at the face.
Regulus Black was somewhere in his mid-teens, with a resemblance to Sirius that ran to about seven features in ten. The transformation had stripped the flesh close to the bone and turned his skin a cold blue-grey. His eyes were open and fixed on nothing, and his body, still wrapped tight in Nicolas's rope, kept straining against the bindings, driven by the curse that animated him, pushing toward the intruders without pause or volition.
Sirius looked at that face for a long time.
The memories that came back were ones he hadn't touched in years. He and Regulus had not always been at odds. When they were small, Regulus had followed him everywhere, calling after him constantly, easily a dozen times a day. That had been the shape of things before Hogwarts, before the Sorting, before the distance that opened between them gradually and then all at once.
Regulus had grown up exactly as their parents wanted. Every manner, every connection, every belief shaped to their specifications, and as far from Sirius as it was possible to be. After enough arguments, they had simply stopped trying to cross the gap.
When Regulus died, it had been during the worst of the fighting, and the news had come in the middle of everything else. Sirius had tried to go home and find out what had happened. He had been turned away at the door. His mother's illness followed not long after, and then she was gone too, and Regulus became one of those questions that had never been answered.
Kreacher's words, his parents' contempt, and now this, Regulus in a place like this for a reason like this, rearranged something in Sirius's thinking that had been sitting undisturbed for a long time.
Regulus had carried what Sirius walked away from. The expectations, the hope, the weight of being the son who stayed. And then, at sixteen, he had joined the Death Eaters, and somewhere in the years that followed he had looked clearly at what Voldemort actually was and decided to act against him, alone, with Kreacher as his only witness, in a cave at the edge of the sea.
Tears moved down Sirius's face without any sound accompanying them. The worst grief rarely announces itself. It tends to arrive quietly, leaving a person breathing in short pulls with nothing to show for it.
The cave was silent. Lupin moved to Sirius's side and took hold of him, a steadying hand that did not let go. Nobody else spoke. There was nothing to say that would have helped, and everyone present seemed to understand that, so they waited instead.
Newt's expression was difficult to read. Regulus's story had pulled something up from his own memory, something about a woman who had gone looking for a way to matter in a situation that had already decided against her.
Tom was not a good person and had never claimed to be. His view of results was simple and unsentimental, and by that measure, Regulus had accomplished nothing. The Horcrux had sat in that cave for years after his death, undiscovered. The sacrifice had not shortened Voldemort's reign by a day.
But he did not despise people who died for what they believed in. He never had.
After a while, Sirius steadied.
"Sorry," he said, to no one in particular. "Wasting everyone's time."
"You're not." Tom shook his head. "The rest of the Inferi are harder to reach from here. We need to go out to the island anyway. Stay here with Lupin."
Lupin nodded. He was honest enough with himself to know that he and Sirius would not be adding much to what was about to happen.
Nicolas cut the cocoon of rope that held Regulus carefully away from the others. Sirius took it with both hands and stepped back with Lupin.
The lake was not simply a body of water with Inferi in it. Voldemort had constructed it as something closer to an engine. Anyone dragged beneath the surface would be converted by the dark energy continuously cycling through it, adding to the supply indefinitely. The cave above had been enchanted to suppress all flight, and the same dark saturation made it difficult for a phoenix to channel its gifts properly here. Every element of the design pointed at one person. Voldemort had built this place assuming only one wizard in the world would ever find it worth destroying.
Tom was curious whether he could fly across on his own. He decided to wait until the lake was cleared before testing it.
"There, there, and there."
He pointed out several locations along the cave walls. "Those are the anchor points for Voldemort's enchantments. Break them and the flight suppression ends. The lake will need time to purify on its own, but the rest can be dealt with now."
Nicolas followed each indication carefully. He had been surveying the cave since they arrived and had identified some of the same points himself, though not as many, and not as quickly.
He looked at Tom without comment for a moment.
"I'm sensitive to magical traces," Tom said, before Nicolas could phrase the question. "The Mage Sight makes trap enchantments obvious. It finds the weakest points automatically."
"Professor, this is your moment."
Tom sent several orbs of light out across the cave, positioning them precisely over each anchor point he had identified. Dumbledore had done nothing physically demanding since they arrived. That was not something Tom was willing to leave unaddressed. Old people needed to stay active.
Dumbledore smiled faintly at the obvious maneuvering. Tom could have handled every one of those points himself. He was being made to participate deliberately, because Tom, in any situation involving effort, made absolutely certain the cost was distributed.
Dumbledore consulted briefly with Nicolas, they settled on an approach, and then the Elder Wand came out. Several beams of gold light left the tip simultaneously, each one finding the position Tom had marked.
There was no explosion. The light entered the stone and vanished. Then the entire cave began to shake, a low sustained tremor that made the ceiling feel unreliable for several uncomfortable seconds. But the worst did not happen. Instead, green energy began seeping out from the walls, Voldemort's magic being driven from its anchors, and Dumbledore was ready for it, the Elder Wand producing a dense golden smoke that caught the expelled energy and contained it.