“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…”