Oubliette
"Ugh… where am I?" Harry asked, sitting up with a groan while trying to rub a massive headache away.
An unexpected ethereal voice answered the question, "Welcome to the Oubliette."
"Where?" Harry asked confused, "I thought they were taking me to Azkaban?"
"Oh, no." the voice replied with a tinkling laugh, "Something about you has them curious. So while the world may think you're in Azkaban, you're really in this place of forgetting."
"I've never heard of this place… the Oubliette."
"Because, like the people that run it, this place is not spoken of." The whispered voice sounded sad, but Harry couldn't tell anything about the person speaking.
"Who are you?" Harry asked.
"A foolish woman." She replied, "A spell researcher trying to figure out what my friend did to save her child from an unforgivable curse…"
Harry was shocked, "You… knew my mother?"
"Harry?" the woman asked.
"Yeah…"
"So since they couldn't get the secrets out of me, they want to try getting them out of you."
"Did you figure out what my mother did?"
"I succeeded, I think… but no one, not even you, can be allowed to know."
"I… understand."
"It's not so bad here most of the time… though I do miss my little moon."
"Little moon?"
"Luna… my daughter. She was playing upstairs, a week from her ninth birthday, when they took me from my lab. I have no idea what's happened to her since then."
"I think I might have met her last year," Harry replied, thinking of the girl wandering the cold castle halls at night shortly after Hagrid had shown off the dragons to be used in the first task, "petite blonde with silvery grey eyes."
"Just like me."
"She's in Ravenclaw." Harry stated, not wanting to divulge that she'd been nude when they met or that her housemates had Confounded the bronze eagle that guarded the entrance to the Aerie to speak nothing by gibberish whenever Luna was nearby. "I'm sure Hermione will look after her."
"Hermione?"
"My girlfriend… at least until I wound up in here."
The woman's voice changed, deepening somewhat, "When Crimson backed with Violet faces Emerald backed with Garnet, Silver, Saphire, and Onyx, the sky will open and time shall fall, the known, unknown and the Heart of Avalon shall rule again. The Shattered Soul made whole, and the four dark lords brought low."
"What?"
"Hmm, did you say something?" the woman asked, her voice returning to what it had been previously, "I must have dozed off for a moment."