That night, under the cloak of invisibility, Harry slipped through the seventh-floor corridor. He paced three times before the blank stretch of wall, focusing on ARC's instructions.
"Think: I need to see the original Room. Not the one Hogwarts shows. The one it hides."
The door appeared.
But what lay beyond was not the cozy room filled with cushions and cauldrons. Instead, Harry stepped into a dim, circular chamber carved in obsidian-black stone. Floating in the air were runes made of light—constantly shifting, rewriting themselves.
ARC buzzed in his mind with excitement.
"Confirmed: This is the Arcane Core of Hogwarts. A sentient, semi-autonomous magical network. Your room is connected to the castle's memory and magical nervous system. No record of this chamber exists in any book."
"Is… Hogwarts alive?"
"Yes. In a sense. And it's trying to speak to us."
Harry reached out toward one of the glowing runes, and it pulsed softly beneath his fingertips.