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.

As a precaution, Mickey O'Rooney had placed new caps upon the tubes, but had chosen to leave the charges themselves undisturbed. This beautiful weapon the lad held grasped in his hand, determined to blaze away at the prowling murderers the instant they should reveal themselves with sufficient distinctness to make his shots certain.

An annoying delay followed. The Apaches seemed to know very nearly where the right spot was, without being able to locate it definitely. The footsteps were heard first in one direction and then they changed off to another. The warriors acted precisely as if they knew the location of their intended victims, but were seeking to find whether they were in the right position to be easily attacked.

Thus matters remained for ten or fifteen minutes longer, during which the lad held himself on the alert, and was no little puzzled to comprehend the meaning for the course of their enemies.

“They daren't do anything, now that they know where we are. They're afraid we're on the watch, and think if they wait a while longer, we will drop off to sleep; but they will find—-”

A sudden light just then broke in upon young Munson. He was looking off in the direction of the sound, when the phosphorescent gleam of a pair of eyes shot out from the darkness upon him.

There was a greenish glare in the unexpected appearance that left no doubt of their identity. Instead of Indians, as he had imagined at first, there was some kind of a wild animal that was prowling about them. None of the Apaches had entered the cave at all—only a single beast.

But where had he come from? By what means had he entered the cave?

These were very significant questions, of the greatest importance to the two who were shut within the subterranean prison. Fred did not feel himself competent to answer, so he reached over and shook Mickey harder than ever, determined that he should arouse.

“Come, wake up, you sleepy head,” he called out. “There might a dozen bears come down on you and eat you up, before you would open your eyes! Come, Mickey, there is need of your waking!”

“Begorrah—but—there's more naad of me slaaping,” muttered the Irishman, gradually recalling his senses. “I was in the midst of a beautiful draam, in which there came two lovely females, that looked like Bridget O'Flaherty and Molly McFizzle. Both were smiling in their winsome way on me, and both were advancing to give me a swaat kiss, or a crack over the head, I don't know which, when, just before they raiched me, you sticks out your paw and gives me a big shake. Arrah, ye spalpeen, why did ye do that?”

“Didn't you hear me say there was something in the cavern? I thought there were a couple of Apaches at first, but I guess it is a wild animal.”

The Irishman was all attention on the instant, and he started bolt upright.

“Whisht! what's that ye're saying? Will ye plaze say it over again?”

The lad hurriedly told him that an animal of some kind was lurking near them. Mickey caught up his rifle, and demanded to know where he was. In such darkness as enveloped them it was necessary that the eyes of the beast should be at a certain angle in order to become visible to the two watchers. Both heard his light footsteps, and knew where the eyes were likely to be discerned.

“There he is!” exclaimed Fred, as he caught sight of the green, phosphorescent ............