"That lets some light on to the subject. You can dismiss the others. Come with me, Tom."
Twenty minutes later Geoffrey stood among the boulders that the shrunken river had left exposed near the foot of a giant cliff which, instead of overhanging, thrust forward a slanting spur into the rush of water, and so formed a bend. It was one of the main obstacles Geoffrey, who wondered at the formation, had determined to remove by the simultaneous shock of several heavy blasting charges. To that end a gang of men had long been drilling deep holes into the projecting spur, and on the preceding day charges of high explosives had been sunk in most of them with detonators and fuses ready coupled for connection to the igniting gear. Geoffrey stood upon a boulder and looked up at the tremendous face of rock which, rising above the spur, held up the hill slope above. The stratification was looser than usual, and several mighty masses had fallen from it into the river. There were also crannies at its feet.
"You've seen all the drilled holes. Anything strike you yet?" inquired Mattawa Tom.
"Yes," was the answer. "It occurs to me that French Louis said he couldn't tally out all the sticks of giant powder that he'd stowed away a week or two ago. I think you foolishly told him he couldn't count straight."
"I did," admitted Tom from Mattawa. "Louis ain't great at counting, and he allowed he'd never let go of the key to the powder magazine."
"I fancy a smart mechanic could make a key that would do as well," remarked Geoffrey. "It strikes me, also, after considering the strata yonder, that, if sufficient shots were fired in those crannies, they would bring the whole cliff and the hillside above it down on top of us—you'll remember I cautioned you to drill well clear of the rock face itself? Now, if coupled fuses were led from the shot holes we filled to those we didn't, so that both would fire simultaneously, nobody afterwards would find anything suspicious under several thousand tons of debris. I'm inclined to think there are such fuses. Take your shovel, and we'll look for them."
They worked hard for half an hour, and then Geoffrey chuckled. Lifting what looked like a stout black cord from among the rubble where it was carefully hidden, Mattawa Tom said: "This time I guess you've struck it dead."
"Follow the thing up," Geoffrey commanded.
This was done, and further searching revealed the charges for which they were searching, skillfully concealed in the crannies. Geoffrey's face was grim as he said:
"It was planned well. They would have piled half yonder shoulder of the range into the cañon if they had got their devilish will. Pull up every fuse, and fix fresh detonators to all the charges. Change every man in that gang, and never leave this spot except when the section boss replaces you, until we're ready for firing. Thank Heaven that will be in a few more days, and my nerves may hold out that long. I've hardly had an hour's sleep in the last week, Tom."