Desperately they labored, eating their way into the heart of the ice. The splinters fell on their warm bodies, for they were perspiring now, and there the frosty particles melted, wetting their garments through.
Suddenly Paul uttered a cry as he dug his knife savagely into the barrier.
"What's the matter—cut yourself?" asked Russ.
"No," was the low-voiced reply. "But I've broken the big blade of my knife. Now I'll have to use the smaller one."
It was a serious thing, for it meant a big decrease in the amount of ice Paul could chop. But opening the small blade of the knife he kept doggedly at the task.
It was growing darker now. They could observe this through the translucent walls of the cave.
"Do you think they will come for us?" asked Ruth, in a low tone.
"Oh, yes, of course. If we don't get back by dark," responded Russ, as cheerfully as he could. "But we'll be out before then. Come on, Paul. Dig away!"
But it was very evident that they would not be out before dark. The ice block was thicker than Russ and Paul imagined.
"Please rest!" begged Alice, after a period of hard work by the two young men. "Please take a rest!"