Andy Foger and his father discreetly behind the first row of Eskimos, when, with a suddenness that was startling, there sounded throughout the whole valley a weird sound!
It was like the wailing of some giant—the sighing of some mighty wind. At the same time the air suddenly became dark, and then there came a violent snow squall, shutting out instantly the sight of the advancing natives. Tom and the others could not see five feet beyond the cave.
"This will delay the attack," murmured Ned. "They can't see to come at us."
Mr. Parker came running up from the interior of the cave. On his face there was a look of alarm.
"We must leave here at once!" he cried.
"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.
