The ancient irrigation channels beneath the Western Rust-Scarp were never meant for living men.
They had been chiseled six hundred years earlier by the high-pressure engineers of the First Salt Dynasty. Huge underground chimney pipes designed to channel raw, acidic stone runoff from the earth-heat cooking pots into the deep evaporation pans of the outer basin. The walls were built of massive, polygonal dark rock cut stone blocks, each weighing three tons, fitted together without iron clamps and sealed only with a dense, grey mortar composed of hardened bone-ash, river lime, and fiery volcanic cement. In those forgotten days, entire rivers of boiling salt water had surged through these tunnels, carving smooth, glassy troughs into the bedrock before the ancient inland seas pulled back. Then it left the world dry.
Now, as Ren stumbled along the slimy floor of the main drainage aqueduct, the stone world around them was literally melting.
The boiling earth-heat salt water released from the collapsed Siphon Tower had flooded the upper galleries of Khor-Sula, transforming the dry channels into high-pressure steam tunnels. Everywhere Ren looked, thick curtains of pale sulfuric vapor hissed through the jagged seams of the ceiling. Where the acidic steam touched the mortar joints, the ancient lime sizzled, effervescing in tiny white bubbles like vinegar poured over chalk. The air tasted of bitter brimstone and crushed bone, so dense that every breath burned the throat like swallowed needles.
