When the lad was certain that he had labored far enough on the back track to take him fully to the camp-fire, he really had not gone more than one-half the distance.  Worse than this, he saw, from the nature of the ground, that he was “off soundings.”  Several times he was forced to leap over openings, or rents, similar to that into which he had stumbled, and the broadening out of the cave made it out of his power to confine his path to anything like reasonable limits.  The appearance of unexpected obstructions directly in his way compelled numerous detours, with the inevitable result of disarranging the line he intended to pursue, and causing his course to be a zigzag one of the most marked character.

There were no landmarks to afford him the least guidance.  In short, he was like the ill-fated steamer caught on a dangerous coast by an impenetrable fog, where no observations can be made, and the captain is compelled to “go it blind.”  He was forcibly reminded of this difficulty by unexpectedly finding himself face to face with the side of the cavern.  When he thought that he was pursuing the right direction, here was evidence that he was at least going at right angles, and, to all intents and purposes, he might as well have been going in exactly the opposite course.

“Well, things are getting mixed,” he exclaimed, more amused than frightened at this discovery.  “I never tramped over such a place before, and if I ever get out of this, I’ll never try it again.”

But there was little cause for mirth, and when he had struggled an hour longer, something like despair began to creep into his heart.  Worse than all, he became aware that his torch was nearly exhausted, and, under the most favorable circumstances, could not last more than an hour longer.

While toiling in this manner, he had continued to signal to Mickey in his usual manner, but with no other result than that of awakening the same deafening din of echoes.  By this time he was utterly worn out.  He had been traveling for hours, or, rather, working, for nearly every step was absolute labor, so precipitous was the ground and so frequent were his detours.  He had accomplished nothing.  When he expected to find himself in the immediate vicinity of the campfire, there were no signs of it, and the loudest shout he could make to his friend brought no reply.

This fact filled the mind of Fred with a hundred misgivings.  He had given up the belief that it was possible for Mickey to remain asleep all this time.  He was sure the night had passed, and, great as was the capacity of the Irishman in the way of slumber, he could not remain unconscious all the time.  And then nothing seemed more probable than that he was placed for ever beyond the power of response.  If a dozen Indians quietly let themselves down through the opening during the darkness of the night, they could easily discover the sleeping figure, and dispatch him before he could make any kind of resistance.