(The Deep Caverns beneath Runestone, Summer 125 AC)
The air down here was ancient. It didn't smell of the sea, nor of the pine forests that covered the mountains. It smelled of compressed time, wet granite, and the metallic tang of deep earth veins.
Deep beneath the foundations of the castle, past the dungeons and the root cellars, lay a natural fissure that Aeryn had expanded into something far more dangerous than a mine.
Casper, the crippled spymaster of the Shadow Bastion, limped behind the Prince. His twisted leg dragged on the smooth stone floor, creating a rhythmic scraping sound that echoed in the gloom. Scrape. Step. Scrape. Step.
"The ventilation shafts?" Aeryn asked, his voice low, devoid of echo due to the acoustic dampening panels he had installed on the walls.
"Functioning, My Lord," Casper rasped. "We used the chimney effect. Cool air is drawn in from the sea cliffs, heated by the geothermal vents below, and rises out through disguised flues in the rookery. The humidity here is stable at 12%. Parchment will not rot. Ink will not fade."
They reached the end of the tunnel.
There, embedded into the living rock, stood the barrier. It looked less like a door and more like the hatch of a bank vault in the Iron Bank of Braavos. It was a circular slab of solid bronze, three inches thick, reinforced with bands of cold iron.
There were no handles. No keyholes in the traditional sense. In the center of the door was a complex mechanism of exposed gears and cogs, culminating in two hexagonal slots, spaced five feet apart—too wide for a single man to reach both simultaneously.
"The locksmiths from Qohor," Aeryn noted, running his gloved hand over the cold metal. "They did good work. The tolerance on these gears is less than a millimeter."
"And they are dead?" Casper asked casually.
"They were paid handsomely and sent back to Essos on a ship that... encountered a rogue wave," Aeryn lied smoothly. Or perhaps he didn't. With the Preceptor working for him now, "rogue waves" were a purchasable service.
Aeryn pulled a chain from around his neck. Hanging from it was a heavy, geometrically complex key made of black iron.
"Give me your hand, Casper."
Casper extended his pale, trembling hand. Aeryn placed a matching key into it. It was heavy, cold, and terrifying.
"This is not a door that opens for one man," Aeryn explained. "It is a Binary Safety System. The tumblers inside the mechanism must rotate simultaneously. If one key turns without the other, the gears lock, and a vial of wildfire inside the casing shatters, fusing the mechanism shut forever. The data dies with the error."
Casper looked at the key, then at the door, then at the Prince. He realized the level of trust—and the burden—being placed in his palm.
"Why me?" Casper whispered. "Why not Ser Vardis? Why not Maester Helaebar?"
"Vardis has honor; he would hesitate to use what lies inside," Aeryn said. "Helaebar has curiosity; he would read what he shouldn't. You, Casper... you have hate. And you have loyalty. That is the correct mixture."
"Insert," Aeryn ordered.
They stepped up to the slots.
Click. The keys slid home.
"Turn on three. One. Two. Three."
They turned.
CLANK-WHIRRR-THUD.
The sound of heavy tumblers falling into place vibrated through the floor like the heartbeat of a giant. The massive bronze door groaned and swung inward on perfectly balanced hinges.
...
(The Vault)
The room beyond was vast, carved out of the mountain's heart.
It was lined from floor to ceiling with shelves made of rot-resistant ironwood. But unlike a library, which is designed to be full, this room was designed to be selective.
In the center stood a single, large table with a map of the Known World etched into its slate surface.
"This is The Vault," Aeryn said.
Casper looked at the thousands of empty slots. "We will need an army of scribes, My Lord. The agents send hundreds of reports a week. Market prices, tavern gossip, who is sleeping with the baker's wife..."
"No," Aeryn cut him off sharply.
He walked to the nearest shelf, his mechanical brace clicking softly.
"We are not garbage collectors, Casper. We are not here to archive the noise of the world."
Aeryn turned, his violet eyes hard in the torchlight.
"If a fishmonger in Gulltown cheats on his taxes, that is a matter for the city watch. It stays above ground. If a merchant complains about the price of wool, that is for the Trade Council. It stays in the offices."
He slammed his hand on the metal shelving.
"This room is for High-Value Intelligence only. Secrets of National Importance. Data that can topple a House, break a siege, or blackmail a King."
Aeryn began to pace, outlining the criteria.
"I do not want to know if Lord Belmore likes boys. That is trivia."
He stopped.
"I want to know if Lord Belmore is taking gold from the High Tower to vote against my interests. That is Leverage."
"I do not want to know the patrol routes of the City Watch in King's Landing."
He pointed to the map on the table.
"I want the blueprints of the secret tunnels Maegor built under the Red Keep. That is Strategy."
"I do not want rumors of war."
"I want the exact number of spears House Lannister can field in ten days, and the name of the banks they owe money to. That is Victory."
Casper nodded slowly, understanding the distinction. "You want weapons, not paper."
"Exactly," Aeryn said. "Information is like ore. Most of it is slag. This Vault is the crucible. We filter out the dirt. Only the pure metal enters here. If a piece of paper enters this room, it means someone dies if it is read."
Aeryn reached into his tunic and pulled out a sealed scroll. It was the first document to be archived.
"This," Aeryn said, holding it up, "is the complete roster of the Iron Veins, including the true identity of the Preceptor and the locations of our safehouses in Pentos and Braavos. If this falls into enemy hands, our offensive capability is wiped out."
He placed it in a slot marked Security - Alpha.
"And this," he pulled out a second scroll, "is a detailed psychological profile of Prince Daemon Targaryen, compiled from twenty years of observations, listing his triggers, his insecurities, and the specific ways to manipulate his rage."
He placed it in a slot marked Threats - Class 1.
"Domestic gossip rots, Casper. Strategic truth is eternal."
Casper limped to the table. He touched the map, tracing the coastline of Westeros.
"So, we filter," Casper said. "My agents collect everything. I burn the chaff. I bring you the wheat."
"You bring me the poison," Aeryn corrected. "And the antidote."
Aeryn looked around the empty cave. It felt heavy. It felt like standing inside a loaded cannon.
"The Red Keep has the Spider," Aeryn murmured. "He weaves a web of whispers. He knows everything and nothing. He drowns in his own secrets."
Aeryn touched the key around his neck.
"We will not drown. We will curate. When the time comes to strike, I will not have to search through a mountain of hay to find the needle. I will walk in here, open a drawer, and take out the knife."
He turned back to the door.
"Seal it."
They walked out.
CLANK-WHIRRR-SLAM.
The bronze door sealed shut. The tumblers spun, locking away the most dangerous truths in Westeros.
Aeryn tucked the key back under his tunic, against his skin. It was cold, but to him, it felt like a heartbeat. He had built a brain for his kingdom, and he had ensured that it would only remember what truly mattered.
"Tomorrow," Aeryn said as they began the long ascent back to the light, "we start the harvest. Tell your birds to stop looking for worms and start looking for vipers."