"Leave here?" repeated Tom. "Why must we? The enemy are out there! We'd run right into them!"
"It must be done!" insisted the scientist. "We must leave the cave at once!"
"What for?" cried Mr. Damon.
"Because the movement of the ice that I predicted, has begun. It is much more rapid than I supposed it would be. In a short time this cave and all the others will be crushed flat!"
"Crushed flat!" gasped Tom.
"Yes, the caves of ice are being destroyed! Hark! You can hear them snapping!"
They all listened. Above the roar of the storm could be made out the noise of crushing, grinding ice-sounds like cannon being fired, as the great masses of frozen crystal snapped like frail planks.
"The ice caves are being destroyed by an upheaval of nature!" went on Mr. Parker. "This one will soon go! The walls are bulging now! We must get out!"
"But the natives! They will kill us!" cried Mr. Damon. "Bless my soul! what a trying position to be in."
"I guess the natives are as bad off as we are," suggested Ned. "They're not firing, and I can hear cries of alarm, I think they're running away."