The hollow was about fifty feet in diameter and half that depth in the center.  On the opposite side were more bushes and rocks, and then a thicket of tall trees of a variety that was strange to them.

“This is what I call hard work,” observed Tom, as they began to fight their way along again.  “I don’t know but what we would have done as well to have waited until morning.”

“Don’t croak, Tom,” said Sam.

“Oh, I am not croaking, but this is no fun, let me tell you that.”

All of the boys were panting from their exertions, and soon they had to call a halt to get their breath.  It was now growing dark rapidly, for in the tropics there is little of what we know as twilight.

“We certainly can’t do much more in this darkness,” said Dick at last.  “I must confess I thought walking in the direction of the cave would be an easy matter.”

“Well, what’s to do next?” questioned Sam, gazing around in perplexity.

This was no easy question to answer.  As if by magic darkness had settled all around them, shutting out the sight of objects less than a hundred yards away.  To go forward was all but impossible, and whether or not they could get back to where they had come from was a serious problem.

“If we can’t get back we’ll have to camp right here,” said Dick.

But they did not want to stay in such a thicket and so they pushed on a little further, until they reached a slight rise of ground.  Then Dick, who was in advance as before, uttered a cry of surprise: 

“A trail!  I wonder where it leads to?”

He was right, a well defined trail or footpath lay before them, running between the brushwood and palms and around the rocks.  It did not look as if it had been used lately, but it was tolerably clear of any growth.

This was something the Rover boys had not counted on, for Bahama Bill had never spoken of any trail in his descriptions of the isle.  They gazed at the path with curiosity.  Tom was the first to speak.

“Shall we follow it?” he asked.

“Might as well,” answered Sam.  “It’s better than scratching yourself and tearing your clothing in those thorn bushes.”

The boys took to the trail and passed along for a distance of quarter of a mile or more.  It wound in and out around the rocks and trees and had evidently been made by some natives bringing out wild fruits and the like from the forest.

“It doesn’t seem to be leading us to anywhere,” was Dick’s comment.  “I don’t know whether to go on or not.”

Nevertheless, they kept on, until they came to a sharp turn around a series of rocks.  As they, moved ahead they suddenly saw a glare of light cross the rocks and then disappear.

“What was that?” asked Sam, somewhat startled.

“A light,” answered Dick.

“I know.  But where did it come from?”

“It was like the flash of a bicycle gas lamp,” said Tom.