With the small confusion of the shoveling stopped they all fell to listening. Far away, so far that it sounded like miles instead of feet and inches, they could hear faint tappings, followed at irregular intervals by the hoarse rumble of falling detritus. David went on his knees at one side of the pit to examine the pipe of the air-line. It was bent and crushed out of shape, and there was no air coming through it, though a subdued hissing proved that the pressure was on, and that the engineer at the portal compressor-plant was still trying to force air into the blocked heading.

While he was kneeling at the pipe, David discovered another ominous threat; his knees were wet, and in the drainage ditch cut at the side of the tunnel a little pool was forming. He knew well what this meant; that death in still another form was creeping upon them. The tunnel had been a “wet” tunnel almost from the beginning, and here was a hint that the great slide might possibly prove to be a dam as well as a barrier. Fortunately, however, there was a slight up-grade in the bore, and it might be hours, or even days, before the highest point, at the working end of the bore, would overflow.

“We are not doing any good here,” he said to the young woman who stood listening with him. “We may as well go back where it is drier.”

The men had scattered as far as the limits of the cavern would permit, and Regnier surrendered his bit of candle to David to light the retreat. In the heading David made a platform of a few of the bulkhead planks and rearranged the coat-cushioned pallet.

“In a little while the close air will make you sleepy,” he told his fellow-prisoner. “When it does, you must get all the rest you can. I am afraid we are in for a long siege.”

She nodded and sat down on the plank pallet, locking her hands over her knees.

“You needn’t be afraid to say what you think—to me, David. In your own mind you are wondering which will come first: hunger, the bad air, the rising water, or the digging away of the slide. I can face what is in store for us as well as another.”

“I don’t question your courage; God knows, you proved it sufficiently by coming in here when you knew what was going to happen—for you practically did know,” he hastened to say. Then: “Some of us men will probably break long before you will. That is why I say you must rest while you can. You may be needed later on—to keep some of us from forgetting that we are men.”

She gave him a tired little smile. “You are giving me a name to live up to. I wonder if I shall be able to do it—at the last?”

“I don’t doubt it for a single moment; I have never doubted it. Did you have dinner before you began on this hideous adventure?”