“It may be one of the spalpeens that got us into all this trouble,” he added, still circling slowly about, with his eyes fixed upon the opening.  “Those Apaches are sharp-eyed, and perhaps one of their warriors has struck our trail, and tracked us to that spot.  If it’s the same, then I does n’t see what he is to gain by fooling round up there.  If he’d be kind ’nough to let a lasso down that we could climb up by, there’d be some sinse in the same, but—–­”

To the horror of both, at that instant there was a flash at the opening over their heads, a dull report, and the bullet buried itself in the very centre of the camp-fire.

“Begorrah, but that’s what I call cheek, as Ned McGowan used to say when the folks axed him to pay his debts.  While we are looking about, and axing ourselves whether there’s anybody else at all around us, one of the spalpeens sinds his bullet down here, coming closer to us than is plaisant.  Did ye obsarve him?”

“I saw nothing but the flash.  Do you think they could see us?”

“Not where we are now.  We’re too far away from the light.  They’ve seen the fire, and be that token they’ve concluded that we must be somewhere near it.”

“But there was but one shot.  Why not more?”

“We’ll get the rest of thern arter awhile.  That’s a sort of faaler, thrown out to see how we take it, as Larry O’Looligan used to say when he knocked a man down.  Now, do ye stand aside, and I’ll answer ’em.”

“You’d better not,” protested Fred.  “They can tell where we are by the flash of our guns.”

“Whisht, now, can’t we move?  Kape back in the dark like.”

The lad moved away several steps, and Mickey, who made sure that his form was not revealed by the light of his own camp-fire, circled around to the other side of the opening, which he was watching with the keenest interest.  His purpose was to catch a glimpse of the wretch who had fired the shot.  But that seemed about impossible.  He could detect something moving now and then, and once or twice there was a twinkle of something red, like the eagle feather in the hair of the warrior, but he could make out nothing definitely.

“He’s there; and all I want to do is to be certain of hitting him,” he muttered, as he held the cocked rifle to his shoulder.  “I’m afeard that if I miss he’ll take such good care of himself that I won’t get another chance—–­”

“There, Mickey, there’s something,” broke in Fred, who was scrutinizing the opening as closely as he could.  “Fire, quick! or you won’t get the chance!”

The words were scarcely uttered, when the Irishman, who had already taken aim, pulled the trigger, instantly lowering his piece to watch the result.

Both he and Fred fancied they heard an exclamation, but they could not be certain.  There was no perceptible commotion about the skylight, but the flickering, erratic movement which had puzzled them ceased on the instant.  Whether the shot had accomplished anything or not could only be conjectured, but Mickey was of the opinion that the exchange was equally without result in both cases.