Beyond the outer edge of the Silicate Forest, the inverted mantle curved into an escarpment of sheer, stone-hard black dark rock that plummeted twenty miles into the void.
Embedded directly into the face of that underground mountain stood the portal to Progenitor Vault Six.
It wasn’t a doorway carved by human hands, nor was it a primitive cave opening. It was a giant stone inner wall sixty meters in width, forged from a rainbow-bright, dull-gold iron-hard metal alloy that had not tarnished in a hundred million years. Nested rings of dark, stone-hard sky wood were inlaid into the metal, pulsing with thin, tiny veins of glowing cyan aether. Across the vast surface of the outer ring, millions of tiny, helical nucleotide glyphs formed fine, detailed fractal mandalas, rotating slowly in place as if calculating the earth-shaking drift of the planet.
Arthur Vance stopped forty paces before the threshold, the soles of his magnetic boots locking onto the polished iron-hard metal apron that extended from the gate.
“Hold position,” Arthur commanded, raising a hand.
Beside him, Titus didn’t wait. The old terrapin moved with a heavy, deliberate sense of purpose that he rarely exhibited during their daily marches. His four massive legs, each thick as an ancient oak trunk, propelled his fourteen-ton frame across the smooth metal apron. His claws clattered with hollow, metal echoes against the iron-hard metal plates until he reached the center of the threshold.
