Harry stepped off the Hogwarts Express with a strange feeling. It wasn't just the shadow of Voldemort growing stronger—there was something else. Something old, humming in the castle stones.
"Harry. There is a persistent arcane signature within the castle. It is ancient, encrypted, and predates modern wandwork. Would you like me to triangulate?"
He hesitated, watching first-years giggle their way into boats and prefects hustle about. Then he whispered under his breath, "Do it. Quietly."
"Initiating passive scan…"
By the time they reached the Great Hall, ARC had already begun mapping the invisible currents that ran beneath the floor. During the feast, Harry barely touched his food.
"Primary signal is originating beneath the dungeons. Secondary echoes are distributed throughout the castle—behind the library, near the astronomy tower, and most intriguingly… the Room of Requirement."
Harry's fork paused mid-air. "That room again?"
"It adapts based on thought, but its foundation was designed using a forgotten form of spell architecture. The enchantment pattern matches no known school of magic. Would you like to access its root matrix?"
Harry smirked. "Hell yes."