Bill and Walter crawled under the shelter of the rocks to a short distance away and then, rifles ready, advanced to the attack. A report came from the hollow and a bullet whined over Bill’s head. Almost instantly a crack came from Walter’s rifle and splinters flew from the building in the hollow a few inches from a loophole, through which projected the barrel of a rifle.
The rifle barrel swung rapidly in a circle and barked in Walter’s direction; but as it did so, Bill’s gun spoke and again splinters flew from the building.
“Good work!” ejaculated Dr. Bird as he watched the slow advance of the two guides. “If we just had rifles we could 302 join in the party, but it’s a little far for effective pistol work. Let’s go ahead, and we may get close enough to do a little shooting.”
Pistols in hand, Carnes and the doctor crawled over the crest and joined the advance. Again and again the rifle spoke from the hollow and was answered by the vicious barks of the rifles in the hands of the guides, Carnes and the doctor resting their pistols on rocks and sending an occasional bullet toward the loophole. The conditions of light and the moving target were not conducive to good marksmanship on the part of the besieged man, and none of the attackers were hit. Presently Walter succeeded in sending a bullet through the loophole. The rifle barrel suddenly disappeared. With a shout the four men rose from their cover and advanced toward the building at a run.
As they did so an ominous whirring sound came from the apparatus in front of the house and a sudden chill filled the air.
“Back!” shouted Dr. Bird. “Back below the hill if you value your lives!”
He turned and raced at full speed toward the sheltering crest of the hill, the others following him closely. The whirring sound continued, and the concave reflector turned with a grating sound on its gears. As the path of its rays struck the ground the rocks became white with frost and one rock split with a sharp report, one fragment rolling down the slope, carrying others in its trail.
With panic-stricken faces the four men raced toward the sheltering crest, but remorselessly the reflector swung around in their direction. The intense cold numbed the racing men, cutting off their breath and impeding their efforts for speed.
“Stop!” cried the doctor suddenly. “Fire at that reflector! It’s our only chance!”