“Goodness!” Dick shuddered, after the passage of one of the tightest of the squeeze holes, “isn’t there any end to this miserable mole burrow?”
It was just a little way beyond this that they found an end; a most curious one. Away ahead they could see faint glimmerings of daylight, and it was coming, not through a single outlet, but seemingly through a dozen. A little farther advance showed them a singular phenomenon. At its outer end the passage they were following was split into numberless cracks and crevices, as if the final barrier of rock had been shattered, but not entirely broken through and carried away, by some mighty volcanic blast. And no one of the crevices was wide enough to let them squeeze through to the open air.
“That settles it,” said Larry, not without keen disappointment. “We’ll have to go back the way we came, and we’d better be doing it, too. This seepage stream really is getting bigger, all the time.”
When they began to retrace their steps it was hard to keep panic from getting the upper hand to turn the retreat into a rout. In the tight places Dickie Maxwell had to shut his eyes and grit his teeth to hold on to his nerve; and Larry, while he took it coolly and more methodically as a thing that had to be done and done right, felt the same naggings of panic in the critical pinches. For now it was plainly apparent that the leakage stream from above was growing in volume from minute to minute.
“Don’t let it get your nerve; we’ll make it all right,” he said to Dick, as he braced himself to pull his lighter companion through one of the mole burrows. But all Dick permitted himself to say was: “Gee! Larry—if we ever get out of this trap alive!—”
They made it finally; or at least they reached the big cavern with the water oozing through its western wall. With an open way of escape through the old prospect tunnel now presenting itself they stopped to catch a breath of relief. It was in this breathing spell that Dick said:
“I guess I know now what your big idea is, Larry.”
Larry nodded.
“You see why we had to go on and find out if this place had a real drain-way to the canyon below the dam. We know it has, now. What I don’t know about engineering would fill the biggest book you ever saw, but anybody can see that a few boxes of dynamite buried up at the head of that prospect tunnel and fired will let the water out of our lake—and do it through these cave holes slowly enough so that it won’t flood everything to death down below.”
Dick did not answer at once. There was a rock ledge at one side of the big chamber and he sat down upon it. When he spoke it was to say: