By supreme effort Judy and Kathleen held their nerves in rigid check. Each step seemed to be taking them deeper and deeper into oblivion. A dozen doubts assailed them. Would Captain Hager ever find the narrow passage leading out of the chamber? And if they should be successful in reaching the siphon, would not the return be even more difficult?
The darkness seemed endless, but finally Captain Hager’s light revealed a rough wall ahead. A wave of relief washed over Judy and Kathleen. But it was short lived.
Their guide had paused to move the flash beam slowly along the solid wall, first to the right, then to the left. He muttered something, but his words were indistinguishable.
The captain deliberately did not answer. After a moment, he started on again, groping along the wall. Kathleen did not repeat her question.
For awhile Captain Hager kept on, the girls directly behind, following blindly. Then suddenly the old man seemed to relax, and they heard him give a throaty chuckle.
Judy and Kathleen already had distinguished the distant sound of running water. The underground stream!
At the same instant that they heard the splash of water, Captain Hager’s flash beam focused upon the narrow opening in the cavern wall--the passageway for which he had searched.
They moved quickly through the narrow corridor. The thunder of a distant waterfall they never were to see, was louder now in their ears.
The floor of the passageway sloped sharply downward. Kathleen slipped but did not fall, for Judy caught her arm to give her support.
Abruptly, the corridor turned, and the girls saw water ahead. The underground stream, quiet and dark, emerged from a wall of rock to flow tranquilly beneath the slightly arched cave-roof above.
Captain Hager halted. “We’ve come to the end,” he announced.
Judy and Kathleen were stunned. “The end,” Judy repeated, scarcely comprehending. “But I thought--”
“We can proceed no further without wading along the river bed,” the captain explained. “The water gradually deepens until it rises to the ceiling. At that point, one must dive through and swim underwater, or turn back.”
He focused his light to the right, and the girls saw the meeting place of wall and water.
“Aye, how far it goes, no man knows. It may extend for only a few feet or yards. Then again, it may run on indefinitely, with nary a pocket of air.”