"We must retreat!" shouted Andy. "Back to the ice cave! They can not get us there!"
"But what about the airship! We must regain that at any cost!" called the professor.
"Wait until these beasts go away!" yelled Andy. "If they get us down it's only a matter of seconds before they'll kill us with those tusks! Run back!"
All turned to execute this command. There was only a narrow opening in the slowly encircling ring of sea lions, and this the adventurers made for, running toward the ice cave. They had passed beyond the mass of the beasts, when a loud cry from Jack startled them. At the same time he pointed ahead.
There, coming on at full speed was a pack of polar bears! The adventurers were between the two forces of enraged animals!
CHAPTER XII
A MYSTERIOUS MESSAGE
"It's all up with us now!" shouted Andy. "I wish I had never come to the north pole!"
"How shall we escape?" yelled the professor.
Not knowing what to do, the whole party stood still. Behind them were the sea lions, roaring and snorting. In front of them, a hundred feet away were the bears, growling and howling.