“None of that,” commanded Jack, sternly.  “Up with them quick or I’ll shoot.”

Three pairs of hands were unwillingly elevated.  Two of the men wore sheepskin jackets and leather helmets and the boys surmised correctly that they had been up in the airplane.  Bob felt certain they were Morales and Von Arnheim, the two who had made the trip to the East to steal Mr. Hampton’s papers and whom he had foiled in that purpose, but who had succeeded in stealing the airplane and making their way to Mexico in it.  The other was a rangy man of about twenty-six, keen and shrewd-looking, and had the appearance of an American.  Evidently he was the guardian of the cave.  And it was he who had moved to draw his weapon when surprised.  A tough customer and one to be watched, thought the boys.

“Face about,” ordered Jack.

They obeyed.

“Keep them covered, Tom,” Jack then commanded.  “Well search them.”

With weapons held ready, the three boys advanced.  At that moment, the caretaker of the cave took one step forward and instantly the lights in both rooms faded out and the cave was in inky darkness.

He had pressed a button in the floor, switching off the lights.

The boys were so taken by surprise that for a moment they did not fire.  Neither did Tom, for fear of hitting them as they were in front of him.  This gave their three enemies an opportunity to shift position and fling themselves prone.

When after their surprise, the boys did fire, their bullets merely pinged against the distant wall and did no damage.  But the flash of their weapons betrayed their positions and answering bullets came uncomfortably close.  One swept Jack’s hat from his head.

From behind them Tom Bodine’s revolver spoke, as the enemy thus betrayed themselves.  The soft thud of a bullet striking flesh, a groan, choked off in the middle, a hasty scrambling to get away from the danger point on the part of the man struck, then silence.

This silence was so profound the boys seemed to hear the beating of their own hearts, and tried to hold their breath for fear of betrayal.  They had thrown themselves prone after the first volley and lay so close they were touching, Jack in the middle.

Each side was fearful now of firing at the other, lest the flashes give their position and an answering bullet find its mark.

Jack thought quickly.  Putting his lips to the ear of each of his companions in turn, he whispered: 

“Wait till I get Tom and come back.  Then we’ll make our way to the entrance.”

Each signified by the pressure of a hand that he understood.  Certainly it would not do to have the enemy escape and thus cut them off in the cave!

Slowly, carefully, noiselessly, Jack wormed his way to the rear and when he considered he must be in Tom Bodine’s neighborhood he began whispering in a tone that could not be heard more than three feet away: