J. Rowling - Harry Potter and the Deathly Hallows

“And one day, a year after he joined, Master Regulus came down to the kitchen to see Kreacher. Master Regulus always liked Kreacher. And Master Regulus said… he said…”

The old elf rocked faster than ever.

“…he said that the Dark Lord required an elf.”

“Voldemort needed an elf?” Harry repeated, looking around at Ron and Hermione, who looked just as puzzled as he did.

“Oh yes,” moaned Kreacher. “And Master Regulus had volunteered Kreacher. It was an honor, said Master Regulus, an honor for him and for Kreacher, who must be sure to do whatever the Dark Lord ordered him to do… and then to c-come home.”

Kreacher rocked still faster, his breath coming in sobs.

“So Kreacher went to the Dark Lord. The Dark Lord did not tell Kreacher what they were to do, but took Kreacher with him to a cave beside the sea. And beyond the cave was a cavern, and in the cavern was a great black lake…”

The hairs on the back of Harry’s neck stood up. Kreacher’s croaking voice seemed to come to him from across the dark water. He saw what had happened as clearly as though he had been present.

“…There was a boat…”

Of course there had been a boat; Harry knew the boat, ghostly green and tiny, bewitched so as to carry one wizard and one victim toward the island in the center. This, then, was how Voldemort had tested the defenses surrounding the Horcrux, by borrowing a disposable creature, a house-elf…

“There was a b-basin full of potion on the island. The D-Dark Lord made Kreacher drink it…”

The elf quaked from head to foot.

“Kreacher drank, and as he drank he saw terrible thing… Kreacher’s insides burned… Kreacher cried for Master Regulus to save him, he cried for his Mistress Black, but the Dark Lord only laughed… He made Kreacher drink all the potion… He dropped a locket into the empty basin… He filled it with more potion.”

“And then the Dark Lord sailed away, leaving Kreacher on the island…”

Harry could see it happening. He watched Voldemort’s white, snakelike face vanishing into darkness, those red eyes fixed pitilessly on the thrashing elf whose death would occur within minutes, whenever he succumbed to the desperate thirst that the burning poison caused its victim… But here, Harry’s imagination could go no further, for he could not see how Kreacher had escaped.

“Kreacher needed water, he crawled to the island’s edge and he drank from the black lake… and hands, dead hands, came out of the water and dragged Kreacher under the surface…”

“How did you get away?” Harry asked, and he was not surprised to hear himself whispering.

Kreacher raised his ugly head and looked Harry with his great, bloodshot eyes.

“Master Regulus told Kreacher to come back,” he said.

“I know—but how did you escape the Inferi?”

Kreacher did not seem to understand.

“Master Regulus told Kreacher to come back,” he repeated.

“I know, but—”

“Well, it’s obvious, isn’t it, Harry?” said Ron. “He Disapparated!”

“But… you couldn’t Apparate in and out of that cave,” said Harry, “otherwise Dumbledore—”

“Elf magic isn’t like wizard’s magic, is it?” said Ron, “I mean, they can Apparate and Disapparate in and out of Hogwarts when we can’t.”

There was a silence as Harry digested this. How could Voldemort have made such a mistake? But even as he thought this, Hermione spoke, and her voice was icy.

“Of course, Voldemort would have considered the ways of house-elves far beneath his notice… It would never have occurred to him that they might have magic that he didn’t.”

“The house-elf’s highest law is his Master’s bidding,” intoned Kreacher. “Kreacher was told to come home, so Kreacher came home…”

“Well, then, you did what you were told, didn’t you?” said Hermione kindly. “You didn’t disobey orders at all!”

Kreacher shook his head, rocking as fast as ever.

“So what happened when you got back?” Harry asked. “What did Regulus say when you told him what happened?”

“Master Regulus was very worried, very worried,” croaked Kreacher. “Master Regulus told Kreacher to stay hidden and not to leave the house. And then… it was a little while later… Master Regulus came to find Kreacher in his cupboard one night, and Master Regulus was strange, not as he usually was, disturbed in his mind, Kreacher could tell… and he asked Kreacher to take him to the cave, the cave where Kreacher had gone with the Dark Lord…”

And so they had set off. Harry could visualize them quite clearly, the frightened old elf and the thin, dark Seeker who had so resembled Sirius… Kreacher knew how to open the concealed entrance to the underground cavern, knew how to raise the tiny boat: this time it was his beloved Regulus who sailed with him to the island with its basin of poison…

“And he made you drink the poison?” said Harry, disgusted.

But Kreacher shook his head and wept. Hermione’s hands leapt to her mouth: She seemed to have understood something.

“M-Master Regulus took from his pocket a locket like the one the Dark Lord had,” said Kreacher, tears pouring down either side of his snoutlike nose. “And he told Kreacher to take it and, when the basin was empty, to switch the lockets…”

Kreacher’s sobs came in great rasps now; Harry had to concentrate hard to understand him.

“And he order—Kreacher to leave—without him. And he told Kreacher—to go home—and never to tell my Mistress—what he had done—but to destroy—the first locket. And he drank—all the potion—and Kreacher swapped the lockets—and watched… as Master Regulus… was dragged beneath the water… and…”

“Oh, Kreacher!” wailed Hermione, who was crying. She dropped to her knees beside the elf and tried to hug him. At once he was on his feet, cringing away from her, quite obviously repulsed.

“The Mudblood touched Kreacher, he will not allow it, what would his Mistress say?”

“I told you not to call her ‘Mudblood’!” snarled Harry, but the elf was already punishing himself. He fell to the ground and banged his forehead on the floor.

“Stop him—stop him!” Hermione cried. “Oh, don’t you see now how sick it is, the way they’ve got to obey?”

“Kreacher—stop, stop!” shouted Harry.

The elf lay on the floor, panting and shivering, green mucus glistening around his snot, a bruise already blooming on his pallid forehead where he had struck himself, his eyes swollen and bloodshot and swimming in tears. Harry had never seen anything so pitiful.

“So you brought the locket home,” he said relentlessly, for he was determined to know the full story. “And you tried to destroy it?”

“Nothing Kreacher did made any mark upon it,” moaned the elf. “Kreacher tried everything, everything he knew, but nothing, nothing would work… So many powerful spells upon the casing, Kreacher was sure the way to destroy it was to get inside it, but it would not open… Kreacher punished himself, he tried again, he punished himself, he tried again. Kreacher failed to obey orders, Kreacher could not destroy the locket! And his mistress was mad with grief, because Master Regulus had disappeared and Kreacher could not tell her what had happened, no, because Master Regulus had f-f-forbidden him to tell any of the f-f-family what happened in the c-cave…”

Kreacher began to sob so hard that there were no more coherent words. Tears flowed down Hermione’s cheeks as she watched Kreacher, but she did not dare touch him again. Even Ron, who was no fan of Kreacher’s, looked troubled. Harry sat back on his heels and shook his head, trying to clear it.

“I don’t understand you, Kreacher,” he said finally. “Voldemort tried to kill you, Regulus died to bring Voldemort down, but you were still happy to betray Sirius to Voldemort? You were happy to go to Narcissa and Bellatrix, and pass information to Voldemort through them…”