the_debt_of_time

vanished an entire family tree out of an ancient book just to keep it away from prying eyes,
he did not feel like he had a leg to stand on in probing for Harry's secrets.
Shortly after, Hermione entered the room looking pale.
"What's happened?" Harry asked quickly.
Hermione's gaze fell on Sirius.
"What'd the elf say?" he asked.
"Volde―"
"Don't say it!" Ron shouted, and the rest of them rolled their eyes.
"You-Know-Who asked Regulus to borrow Kreacher years ago. He took him to
the cave where he was keeping the locket. He made Kreacher drink the potion that
Dumbledore took," she glanced back to Harry. "You-Know-Who used Kreacher to put
the security measures around the locket. Then he left him there to die. But Regulus had
ordered Kreacher to always return to him, so he did."
She moved to the sofa, sat down next to Sirius, reaching for his hand. "Kreacher
told Regulus what he'd done, and Regulus figured out You-Know-Who had made at least
one Horcrux. He had Kreacher bring him back to the cave to retrieve it. He drank the
potion himself and switched the lockets. Gave the Horcrux to Kreacher and told him to
destroy it."
"Regulus drank the potion?" Harry asked quietly, and Hermione nodded. "The
Inferi?"
Sirius saw Hermione nod just before turning his focus down at both of her hands
wrapped around one of his. Her words ran over and over in his mind, and he turned his
attention to his other hand, holding a glass of firewhisky.
"Kreacher said he went beneath the water."
He could hear the tremble in her voice, and a part of him hated the pity he felt
coming off of her. The rest of him wanted to bathe in her comfort. She pulled one hand
away, and he looked up to see her wiping away stray tears from eyes that were now focused
exclusively on him.
Unwilling to speak about his brother's death or potential redemption, Sirius avoided
the subject of Regulus entirely, breaking the silence with, "So... where is it now?"
"Umm," Hermione stammered for a moment. She looked like she wanted to push
him until he disclosed the history between his brother and himself.