The return journey through Trench 05 was bathed in the calm, rhythmic silence of a successful extraction.
Titus glided through the underground channels, his webbed flippers carving smooth, easy strokes through the cooler turquoise water as they left the boiling fiery drain tubes behind. The giant tortoise kept a steady cruising speed of eight knots. His streamlined was dark rock back shell parting the underground water bed currents without creating surface chop. Pip flew lazily fifty paces ahead, perching periodically on protruding stalactites to preen his radiant golden feathers, shaking off the last oily traces of sulfur vapor.
Arthur Vance sat back against the tortoise’s dorsal ridge, one hand resting on the shaking-dampened frame of Echo’s tank. The little axolotl had fully recovered from his panic. Floating midway in his filtered water column, Echo was watching the limestone formations glide past, his tiny pink toes twitching in rhythm with Titus’s flippers.
An hour later, the dark fiery dark rock gave way to familiar porous limestone strata. The underground channel widened into the massive vaulted cave of the railway spur.
Across the underground lake, the warm amber halogen work-lights of the Iron Ark cut through the limestone mist. Sentries in heavy leather coats walked their beats along the raised narrow-gauge rail tracks, their rifles slung across their chests at low ready. Below the tracks, commoner mechanics and refugee families were gathered around small iron stoves, boiling wild cave-mushrooms and dried grain rations. The aroma of woodsmoke, roasted tubers, and machine oil…
