The tunnel they were now in was as black, as dismal and as mysterious as the one they had walked through, starting at Uncle Tod’s camp and ending at the heap of stones. They went carefully, to avoid falling into holes or deep cracks, and swung their lanterns to and fro. Ruddy, contrary to his usual habit, did not run on ahead, to explore on his own account. He kept close to the boys as if afraid.
The tunnel wound to right and left, like some gigantic snake. It was about twenty-five feet wide on the average, sometimes more and sometimes less. In places the roof was not more than ten feet above the heads of the boys and, again, they would be unable to see it in the gleam of their most powerful flash lights.
“Must be a hundred feet up or more,” said Rick after one of these tests.
“I believe you,” Chot answered.
On and on they went, stopping now and then to listen for any sound that would indicate water. But no trickling, murmur or a louder thunder, that might mean a hidden waterfall, came to their ears.
“Where do you reckon that river is?” asked Chot, after a while.
“You’ve got me,” admitted Rick. “But it has been here, that’s sure, and we haven’t come to the end yet.”
This was true, for the tunnel still stretched its black, winding and mysterious length ahead of them. The way was not without its dangers, for, more than once, Rick found himself stepping on the very edge of a black hole.
And once Chot would have fallen into a dismal chasm but that he caught hold of a projecting spur of rock and so saved himself. However these dangers seemed to the boys no more than others they had encountered when on previous excursions afield and in the forest. They were young and active, and to them a miss was as good as a mile, or “even a mile and a half,” as Rick said.
It was nearly noon, which fact Chot ascertained by a look at his cheap but reliable watch, and he was about to propose that they stop and eat when suddenly the hitherto silence of the tunnel was broken by a strange, mysterious noise. It was like some dismal giant groaning in agony.