The boy could not help turning a trifle pale as he realized what an exceedingly narrow escape he had had. Cal's countenance blazed with fury.
"The—the dern—skunks!" he burst out, unlimbering his well polished old revolver.
"Reckon two kin play at that game."
But Nat pulled the other's arm down.
"No good, Cal," he said, "the best thing we can do is to get out of here as quickly as possible. One man up there behind those rocks could wipe out an army down in here."
Cal nodded grimly, as he recognized the truth of the lad's words. Truly they were in no position to do anything but, as Nat had suggested, get out as quickly as possible.
As they reached this determination another bullet whizzed by and struck a rock behind them, doubly convincing them of the wisdom of this course. Fortunately, as has been said, the boulder had rolled clear across the floor of the narrow canyon, such had been its velocity. This was lucky for the lads, for if it had obstructed the way they would have been in a nasty trap. With no room to turn round and no chance of going ahead their invisible enemies would have had them at their mercy.
But if they could not see the shooters on the hillside, those marksmen appeared to have their range pretty accurately. Bullets came pattering about them now in pretty lively fashion. Suddenly Herr Muller gave an exclamation and a cry of mingled pain and alarm. A red streak appeared at the same instant on the back of his hand where the bullet had nicked him. But this was not the cause of his outcry. The missile had ended its career in the case in which he carried his photographic plates.
Nat heard the exclamation and turned about as the car began to move forward.
"Where are you hurt?" he asked anxiously, fearing some severe injury might have been inflicted on their Teutonic comrade.