The Iron Citadel did not welcome them; it inhaled them.
As Corvin and Kael stepped through the gargantuan mandibular archway of the skull, the temperature plummeted into a dry, abrasive cold that tasted of millenia-old bone dust. The air didn't move; it vibrated. It was a low-frequency thrum that resonated deep within Corvin's marrow, making his teeth ache and his 'Crimson Leak' pulse in agonizing rhythm with the Citadel's dying heart.
"Stay close," Corvin rasped, his hand gripping the boy's shoulder. His left arm was now a dead weight, the violet necrotic veins from the shadow-spear wound having crawled up to his collarbone. He looked like a man being slowly overwritten by a darker script.
They were in the 'Vocal Chambers'—a series of interconnected cathedrals made of polished ivory and reinforced with brass ribbing. Thousands of 'Forgotten' hung from the vaulted ceilings in dormant clusters, their gear-fused limbs interlocked like a tapestry of rusted silver.
They weren't attacking, but their collective breathing—a mechanical wheeze that sounded like a thousand bellows—filled the chamber with a suffocating sense of dread.
"The Loom is below," the Marrow-Priest whispered, his brass visor reflecting the dim, jaundiced glow of the lanterns. "But the Citadel is no longer a graveyard. It has become a womb for something that refuses to be born."
They passed through a corridor lined with 'Resonance-Taps'—massive, biological needles that were drained of the Titan's remaining essence. Corvin saw the tubes leading toward the center of the Citadel, pulsating with a rhythmic, golden light.
"Valerius is feeding the machine," Corvin noted, his kinetic blade sparking weakly as he sensed the massive energy draw. "He's not just looking for the Seed; he's preparing the soil."
"Kael..." Corvin stopped, noticing the boy had gone pale. Kael was staring at one of the tapping-vats. Inside, suspended in a thick, amber fluid, was a human figure. Its skin was translucent, its veins replaced by glowing silver wires.
"They're making more of them," Kael whispered, his voice trembling. "The 'Hollow-Gods'. They're using the people from the slums to build vessels for the Void."
"Not just vessels," the Priest corrected. "Mirrors. They seek to create a resonance so pure it will shatter the Gaps and bring the Titans back into the world of flesh. But a Titan without a soul is just an engine of destruction."
Suddenly, the floor beneath them groaned. A massive, tectonic shift echoed through the Citadel, followed by a sound like a thousand harpoons being fired at once. The 'Golden Relic'—Valerius's flagship—had docked with the Citadel's exterior, its boarding spikes piercing the Ivory Skull.
"They're here," Corvin growled, drawing his blade. The friction ignited, but the glow was flickering, his internal energy-reservoirs nearly empty. "Priest, take the boy to the Oscillator chamber. I'll hold the throat of this place."
"No," Kael said, his hair beginning to flicker with that oily obsidian light. "We go together. The Loom is calling me, Corvin. I can hear the song. It's not a prayer... it's a scream."
The shadows at the end of the hall began to swirl. The blue mist of the Wraith-Guard was bleeding through the cracks in the bone-walls. The pursuit hadn't ended; it had simply entered the heart of the nightmare.