At one hundred and sixty yards, the passage dipped into a flooded underground bend. The water was fourteen inches deep, cool and clear, running over a bed of polished river gravel.
Here, Pella noticed an extraordinary living divergence that had caught Imran’s attention in Harrowby. Along the eastern wall of the pool, the native river ribbon organisms—long, semi-clear aquatic mosses that thrived in cold mountain waters—were growing in lush, emerald-green clusters. But along the western rock ledge, six inches above the waterline, the lantern beetles had fully vanished.
Pella knelt on the underwater gravel. She reached out to touch the dry limestone of the western ledge. She pulled her fingers back with a sharp hiss of surprise.
‘Eren, feel this stone,’ Pella whispered. Eren touched the limestone face. The rock was dry, blistering hot—thirty-eight degrees—streaming heat like the outside wall of a bread oven.
‘There is fire behind this stone,’ Eren muttered. He tapped the wall with the butt of his cold chisel. The limestone gave back a hollow, ringing ping. It was followed by the faint, muffled hiss of high-pressure steam escaping through a fractured seam.
Through the Courtesy slate, Imran’s voice was urgent: ‘Pella, don’t step on that western ledge! The beetles know what they’re doing. The rock shelf is less than four inches thick. There is a high-pressure steam leak directly behind the wall. The heat has turned the mortar between the stones to crumbly chalk. If you put your weight on that ledge, the stone will…
