With each step the sound grew louder. It was not the harsh, spasmodic roar of water dashing among sunken rocks, but resembled rather the swift outpour of a torrent gliding over a smooth, unbroken bed.
"Here we are," cried Chutney. "I nearly stepped in the water without seeing it."
He held his torch out with one hand, and its glowing radius revealed a strange sight.
Twenty yards to their left a rapid, unbroken sheet of water burst with terrific force from a dark archway in the very face of the smooth cliff. It was the outlet of the lake.
In width it was about forty feet, though the opposite side of the river was shrouded in darkness. On the spot where they stood a reflux current had worn an inlet into the sandy shore, and here a stretch of comparatively calm water was circling in swirling eddies, a startling contrast to the furious sweep of the torrent beyond.
Yes, there was no doubt of it, here was the continuation of the underground river, the way that led to safety and hope.
With strange emotions they watched in silence the dark flood pouring from its natural archway in the face of the cliff. To their right the sandy shore seemed to spread away smoothly into the darkness, but before they could scrutinize their surroundings more closely a strange, sharp sound echoed through the vaulted roof of the vast cavern, succeeded by a faint shout.
"It was the report of the Greek's rifle," exclaimed Melton, in horror-stricken tones, "and it was Carrington who shouted. Some calamity has happened."
Staggering with fear, they hastened back to the edge of the cliff. Melton clutched the dangling rope.
"Stop!" cried Guy, in tones of agony. "My heavens, Melton, we are lost, doomed to the most horrible of deaths. What blind, desperate fools we were. We can never get back to the lake, and our companions can never reach us here. We could not be more widely separated were the world itself rolling between us."