Marwyn led Aegon through most of the complex, past rows of lecture halls and towers built of grey stone, all the way to the rear of the Citadel.
Beyond it lay the sea.
The Isle of Ravens sat in that bay, where the maesters trained their ravens. The outlines of low buildings were faintly visible on the island, with black specks circling overhead.
Marwyn stopped before a rather desolate building.
It was a three-story round tower, standing alone in the middle of a courtyard.
The weeds on either side of the path had grown knee-high, and vines covered the tower walls.
Clearly, no one had visited this tower in a long time.
"This is where the Citadel stores its forbidden books," Marwyn said. "Scholarly works, notes, documents-anything the Grey Sheep deem heretical, anything the accepted schools of thought refuse to recognize-is sealed away here."
"They refuse to destroy them, because there might still be a useful passage or two within. But they refuse to let young maesters read them either, for fear those ideas might corrupt their minds."
"So they lock them up here and leave them to rot."
As he spoke, he approached the tightly shut, iron-bound oak door.
He drew a black iron key from inside his robes. Scholars who earned the title of archmaester were said to receive such a key, capable of opening any door in the Citadel.
He inserted the key into the lock and turned his wrist. A stiff series of clicks sounded.
The lock opened.
Marwyn pushed the door open.
Stale air from years of confinement washed over them, carrying the mingled scent of old paper and dust. It was not damp, however; the Citadel had taken measures to protect its book repositories from moisture.
He waved his sleeve to disperse the dust