The Sentinel's body felt like lead as I dragged it into the narrow wardrobe, locking the door with his own keycard. My hands were shaking, the metallic scent of the struggle hanging heavy in the recycled air of the cabin. I grabbed the Black Ledger, my fingers tracing the embossed circle—a symbol of the very power that was currently hunting me through the iron bowels of the Acheron.
"Elias! Get out of there!" Maya's voice hissed from the vent. "The Sentinel's vitals were linked to the bridge. They know his heart stopped. You have less than two minutes before they vent the deck with sleeping gas."
I didn't argue. I scrambled into the ventilation shaft, the cold shock-baton tucked into my belt. The crawlspace was a labyrinth of rusted copper and screaming steam pipes. We moved like shadows through the ship's skeleton until we reached a vantage point overlooking the Communications Hub. Below us, two technicians were frantically hovering over a holographic display. The Circle logo pulsed on every screen, but it was flickering—interfered with by a signal coming from the very coordinates we were approaching.
"Look at the frequency," Maya whispered, pointing through the grate. "That's not a standard transmission. It's an SOS embedded in a decryption loop. It's Jeffrey."
"Jeffrey is dead, Maya," I whispered back, my eyes fixed on the pulsing light.
"His body is. But his 'Digital Twin'—the AI he built to manage the Ledger—is still active at the Empty Center," she explained. "The Circle isn't ushering us there to recover the book. They're using us as a 'Human Key.' The vault only opens for a biometric match of an Auditor."
Suddenly, the ship groaned, a violent shudder throwing us against the metal casing. The engines were reversing. We weren't just approaching the coordinates; we were being pulled in by a magnetic tether.
"They're docking," I realized, looking at the monitors. "But not at a port."
On the main screen, the ocean floor began to open, revealing a massive, illuminated structure rising from the trench. It was the Empty Center—a cathedral of glass and black steel submerged in the abyss. I gripped the Ledger. I was the key, the virus, and the victim all at once. The final audit was about to begin.