“Down low; down low; down low,” came whispered back from man to man.
They stooped to an almost creeping posture and began to climb. The ascent was steep as a stair. Twice Dave lost his footing, and once came near sending his rifle crashing to the frozen earth. Some one behind was less fortunate. There came the clang of steel, then deathly silence.
Again they crept upward. Suddenly a ray of light cut through the gloom. In another second, they were in a veritable flood of light. And yet, as they glanced rapidly to right and left, they saw walls of rock. Above them too was a vaulted ceiling. Only before them was light. What could it mean?
In an instant they knew. Leaping toward the opening, they expressed their surprise in unchecked exclamations.
“A balloon! A balloon!”
It was true. It seemed to them, as they looked, that the whole side of the mountain had burst open and allowed a giant dirigible balloon to float out from its depth.
What had really happened was evident. These robbers, having located the rich mine and having no concession to mine it, had discovered this natural cave and had cut a channel from it to the place of the gold deposit. They had reached the point by balloon. Having deflated it, they had stowed it away in the cave and had blocked the entrance of the cave with snow. The next blizzard had defaced every sign of their presence. Doubtless there had been a small secret entrance to the cave which none of Johnny Thompson’s men had discovered.
“They’re gone!” exclaimed Dave.
“And I ’ates to think ’ow much gold they took with ’em,” mourned Jarvis.
“Quick, the airplane!” shouted Pant, turning to the two aviators. “There’s a machine gun on it. We’ll halt them yet. I better go with you. Some of the rest of you explore the interior here. They may not have taken the gold.”