Regulus stood in front of the black stone door, looking for a way in. He couldn't see anything but a blank wall, but he knew the door was there.
"There has to be a way to open this," Regulus said. His voice was quiet, not loud enough to wake the echoes in the high-ceilinged cavern. But what?
Then he realized what would be required. It was the same thing Voldemort always required, sooner or later, from all his followers.
"Of course." Regulus drew a knife from somewhere inside his robes. With a dim flash that barely showed in the dark cave, he sliced it across his arm.
Regulus held the bleeding cut in his forearm against the stone of the door. The stone seemed to absorb his blood like a sponge. After a few seconds, the door opened.
There was more darkness beyond it, even deeper than the darkness in this entry cave. Regulus brought out his wand and whispered, "Lumos." Armed with that small but piercing light, he walked through the door, reflecting that it was probably a good idea to have his wand out anyway.
Regulus had been born and raised in the world of Dark wizarding. His middle name, Abraxas, had been given after a family friend, the father of the boy who would grow up to marry Narcissa. And no one had been surprised when, like his sisters but unlike his older brother Sirius, he had been sorted into Slytherin.
For the past two years, since he had graduated from Hogwarts, Regulus had been a Death Eater in service to Lord Voldemort. But over time, he had begun to feel worse and worse about the evil things he and the other Death Eaters did.
Regulus stopped. He had reached the edge of a wide underground lake, with a small island far away in the center. A green, sinister light shone from the island, and Regulus knew that had to be where Voldemort had hidden the Horcrux.
But how to get there? Regulus stood for a minute and stared at the water of the lake. He had swum easily enough into the main entrance of the cave at the bottom of the cliff, but he knew better than to try and swim in this water.
"There has to be a boat," Regulus decided. "If you can't swim across it, there has to be a boat." He turned right and started walking along the lake's edge, searching for any sign of the boat he was sure must be hidden somewhere.
Halfway around the lake, Regulus stopped. He could see nothing unusual, but the same feeling that had let him find the door told him there was something different here.
Regulus stood very still and closed his eyes. In the water... There was something in the water, and stretching out of it onto the stone at his feet. Without opening his eyes, Regulus reached down to feel what it was.
His hand touched an ancient, crusty chain. The links were as big around as a Golden Snitch, but longer. Keeping his eyes closed in case opening them would make it vanish, Regulus started to pull in the chain.
When he heard a scraping sound on the bank, Regulus finally opened his eyes. There was a small, decorated boat there, the same ancient green copper as the chain that Regulus could now see.
Regulus stepped into the boat and sat down. Slowly, the boat started to move toward the distant island.
He stared at the green light, waiting for what seemed like forever as it drew gradually closer. Finally the boat scraped onto the stone of the island and stopped.
Regulus got out of the boat and onto the island, feeling apprehensive but also confident. He knew that he would die because of doing this, but he also knew that he would not fail.
The source of the green light was now obvious. In the very center of the island was a low pedestal, about waist-high, with a basin on it. Filling the basin was a bright green, glowing liquid.
Regulus stared into the potion, knowing that if he wanted the Horcrux he would have to get past it. After thinking for a few moments, he realized that there could be only one way.
I'll have to drink it, he thought. Voldemort would never allow someone to just reach out, grab his Horcrux, and walk away. He also knew that Voldemort would have made that as nearly impossible as he could.
Regulus could think of only one way to make sure that he did not fail at what he had come here to do. But first, he needed a way to drink the potion. He extinguished his wand-light and conjured a heavy crystal goblet, using a spell he had learned in Charms class at Hogwarts during one of his early years.
Then Regulus gathered his will. He pointed his wand directly at his own chest and said in a firm voice, "Imperio!"
Regulus felt the spell take hold of him. "Drink the potion," he instructed himself. "Drink all of it, no matter what happens. Then take the Horcrux and do whatever it takes to get out of here."
Stepping immediately to the basin, Regulus dipped in the goblet, filled it with potion, and drank it all at once. It burned painfully on the way down to his stomach.
"So, my youngest Death Eater has come to steal my Horcrux."
Regulus spun around at the sound of the familiar, high-pitched voice. But the voice was neither quite so high-pitched nor so cold, and the wizard standing there was much younger than the Dark Lord Regulus knew.
"I know you aren't Voldemort," Regulus said. "You're only his Horcrux. I don't fear you."
Voldemort laughed a hissing laugh. "Do you fear the real me?"
"It doesn't matter," Regulus answered. "I'm here to destroy you."
Voldemort pointed his wand at Regulus. The Dark Mark on Regulus' arm started to burn, like a summons but much worse. Regulus ignored it and stared angrily at Voldemort.
"Keep drinking my potion if you dare, Death Eater," Voldemort said. "You'll find that it is not so easy as you imagine."
Regulus turned back to the basin and scooped out another gobletful of potion. As soon as he drank it, he found himself in a wild hailstorm. The temperature was far below freezing, and tiny, sharp chips of ice that were even colder struck at him from all directions. Seared by the icy chill, Regulus filled his third goblet.
He drank the potion and the hailstorm vanished. Instead, a seething nest of cobras boiled around his lower legs, striking him through his robes and his trousers. Horrified by the feeling of the deadly venom flooding into his legs, Regulus drank another goblet of potion.
The cobras disappeared, to be replaced by a circle of werewolves. Regulus faltered in terror as they howled in one voice and leaped toward him.
Keep drinking! The voice of the Imperius Curse reminded him of what he had to do. The werewolves slashed at his body with their claws, and opened their mouths to bite him, but Regulus filled his goblet from the basin again and drank.
Voldemort was standing in front of him again. "Were my werewolves not enough for you? Perhaps this will be." He touched the tip of his wand to Regulus' chest. "Crucio!"
Regulus screamed in terrible pain and grabbed the edge of the basin to keep himself standing. Through the agony of the Dark Lord's curse, Regulus knew he had to keep drinking the potion. He filled another goblet and swallowed it, terrified of what it would bring.
Fire blazed around Regulus and burned in his flesh, bringing a pain that seemed even more terrible than the Cruciatus Curse. Desperately he scooped out one more goblet of potion from the basin and drank it.
Regulus stopped feeling any pain, but he had no time to wonder why. He saw his brother Sirius standing in front of him, and now Sirius was the one who was on fire and screaming.
Sirius! Regulus stared, frozen in complete horror, but another voice spoke inside of him as well. Keep drinking, the curse insisted. With a terribly shaking hand, Regulus dipped his goblet into the basin again, filled it, and drank it down.
A hundred fist-sized stones slammed into Regulus from every direction, knocking him back and forth and bruising him, and making him wonder dizzily, as he reached for another glass of potion, if the one about Sirius had really been all that bad.
Of course it wa-- "Aaaaahh!" Regulus screamed as every bone in his body snapped into several pieces. Unable to wonder how he was still standing, Regulus scooped up another goblet of potion and drank.
Regulus felt a terrible pain high in his back, between his shoulderblades. Turning around, he saw an enormous acromantula standing behind him with poison dripping from its fangs. He fell to the ground as the spider's venom started to work on his body, and terror flooded through him as the monster's cold eyes stared into his own.
You have to drink it all, the Imperius Curse whispered in his mind, and Regulus agreed. "Yes, that's what I want to do." He reached up to the basin from where he was lying on the ground and filled his goblet with potion.
He drank the potion, and suddenly the acromantula was no longer there. His soul froze when he saw what had taken its place.
A vampire was bending over him, unclean thirst shining in its blood-red eyes. It knelt by his side and sank its teeth into his throat, greedily drinking his blood, and Regulus was too weak to push it away.
Drink the potion! Regulus reached up again and filled his goblet, then brought it down to his mouth and drank it. A deadly cold filled the air of the cave.
There was a horrible rattling sound, and Regulus looked up into the faceless hood of a dementor. It was only inches from his face, but Regulus could see almost nothing through the darkness that closed in on every side. Despair filled him, and he could think of nothing but that the dementor would take his soul, and he would fail.
Drink it! From far away Regulus heard a voice that sounded like his own, telling him what to do. He stretched his arm up and scraped the goblet across the bottom of the basin one more time.
Instead of filling with potion, Regulus felt the goblet strike against something hard with the ring of glass on metal. He dropped the goblet, reached past it, and closed his hand as tightly as he could on Voldemort's Horcrux.
The dementor vanished, but the darkness remained. Regulus lay on the ground and felt that he would never be able to move again.
Get up! He dragged his hand, with the Horcrux, out of the basin and shakily pushed himself to all fours. A blazing thirst filled him, and Regulus crawled to the edge of the lake and plunged his face into the water.
As soon as his thirst was relieved, Regulus remembered that he had to leave the fake Horcrux he had prepared for Voldemort. He managed to stand up, and pulled the golden locket out of his robes, stowing the real Horcrux in the sealed pocket where the fake one had been.
Regulus was about to put the fake Horcrux in the basin when he heard a sound behind him. He dropped the locket in the basin and turned around to see a horrible sight that he knew was no vision.
On the island's shore where Regulus had put his face in the water, a dozen Inferi were climbing slowly out of the lake. Behind them and around them, hundreds more rose out of the water's surface.
Regulus pointed the wand he was still holding at the nearest Inferius. "Lacarnum inflamarae!" he called wildly as the undead creatures surrounded him. "LACARNUM INFLAMARAE!" Blue fire sprang from the tip of his wand, and he spun in a circle, wielding it like a torch to drive the Inferi away.
The Inferi stepped back a few paces, just out of reach of his wand. They did not challenge him as he climbed back into the boat, but they followed closely.
Regulus kept his wand ready as the boat carried him slowly back across the lake, but none of the Inferi tried to attack. They stared silently at him, and when the boat finally reached the distant edge of the lake, they slipped under the water and disappeared.
Regulus got out of the boat and walked back around the edge of the lake, still watching for an attack from the Inferi. But the water remained still, and they did not show themselves again.
At the end of the passageway that led to it, Regulus came back to the stone door he had opened on the way into the cave. It was closed again. Regulus pressed his still-bleeding forearm against the stone, and the door opened to let him through.
There was one more obstacle to prevent him from leaving the cave. Extinguishing his wand and tucking it into his robes, Regulus dived into the icy water where the ocean flowed partway into the cave.
Regulus swam as strongly as he could through the narrow crevice in the face of the cliff and out into the open water. Pulling himself onto a ledge of wet stone, Regulus closed his eyes, concentrated on where he was going, and Disapparated.
He appeared in the middle of his own living room, and the Imperius Curse released him. Wet, shivering, and exhausted, Regulus fell into a chair and fell asleep with the Horcrux of the Dark Lord still in his pocket.