Before consciousness entirely departed, he turned upon his side, that being the posture he generally assumed when asleep.  As he made the movement and his ear was placed against the blanket, which in its turn rested upon the ground, he heard something which aroused his suspicions instantly and he raised his head.  But when he rested on his hands, with his shoulders thrown up, he could hear nothing at all.  The earth was a better conductor of sound than the atmosphere, which accounted for what at first seemed curious.

The boy applied his ear as before, and again he heard the noise, faintly, but distinctly; As the eye was of no use, he pressed his head against the blanket and listened.  Several minutes were occupied in this manner, and then he said, in an undertone: 

“I know what it is!—­it is somebody walking as softly as he can.  There is another way of getting into this cavern, and those Apaches have found it out.  They’ve got inside and are hunting for us!”

CHAPTER XXXIII WHAT THE FOOTSTEPS MEANT

Careful listening convinced Fred that there were two red-skins groping around in the darkness.  After making himself certain on that point, he reached his hand over, and, grasping the muscular arm of Mickey O’Rooney, shook his companion quite vigorously.

Fred was afraid that, in waking, the Irishman would utter some exclamation, or make such a noise that he would betray their location.  When, therefore, several shakings failed to arouse him, the boy easily persuaded himself that it was best to leave him where he was for a time.

“I can tell when they come too close,” he reflected, “and then I will stir him up.”

A few minutes later he found that he could hear the noise without placing his ear against the blanket; so he lay flat on his face, resting the upper part of his body upon his elbows, with his head thrown up.  He peered off in the gloom, in the direction whence the footsteps seemed to come, looking with that earnest, piercing gaze, as if he expected to see the forms of the dreaded Apaches become luminous and reveal themselves in the black night around.

No ray of light relieved the Egyptian blackness.  The camp-fire had been allowed to die out completely, and no red ember, glowering like a demon’s eye, showed where it had been.  The trained eye might have detected the faintest suspicion of light near the opening overhead, but it was faint indeed.

“They keep together,” added Fred to himself, as he distinguished the soft, stealthy tread over the ground.  “I should think they would separate, and they would be the more likely to find the place between them; but they want to be together when they run against Mickey, I guess.”

The shadowy footsteps were not regular.  Occasionally they paused, and then they hurried on again, and then they settled down into the stealthiest kind of movement.  The lad, it is true, had the newly found revolver, with several of its chambers loaded, at his command.  There was some doubt, however, whether it could be relied upon, owing to the probable length of time that had elapsed since the charges were placed there.