"Come on, Parker, my dear man!" begged Mr. Damon. "We are in grave danger, and we need your help. Bless my life insurance policy! but I never was in such a state as this."
"We may soon be in a worse one," was the answer of the gloomy scientist.
"What do you mean?" asked Mr. Damon, but he hurried on without waiting for a reply.
Suddenly, from without the cave came a series of fierce yells. It was the battle-cry of the Indians. At the same moment there sounded a fusillade of guns.
"The battle is beginning!" cried Tom Swift, grimly. He held his electric gun, though he had not used it very much in the previous attack, preferring to save it for a time of more need.
As the defenders of the cave reached the entrance they saw the body of natives rushing forward. They were almost at the gold hole, with 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.