Then he knew, as it came again. There was a sudden movement beneath them. The sled lurched crazily. Conley was shouting something, as their sled pulled up beside Kaarji's, which was lying half on its side.
The men stepped down. Again there came that sudden movement, and Jim nearly fell! Startled, he looked down and saw that the very ice cap was moving beneath their feet, or rather it was expanding! Long lines began to appear in every direction. As far as he could see, the surface was a vast mosaic pattern.
Conley stood there with his hands on his hips, staring around. Wessel was cursing softly and looked angry.
"This wouldn't have happened," Wessel said, "if you'd taken my advice and left two days ago! Tomorrow it'll be worse. It'll slow us to a walk. We may as well not have brought along any sleds."
"It would've happened anyway!" Conley snapped testily. "It's just our damnable luck that it had to come early this year. I didn't expect this to start for another month yet. Well, we may as well camp here and get a good start in the morning."
Jim looked at the mosaic pattern across the ice and was relieved to see that it had stopped moving. He peered down into a crack an inch wide, where a billowing powdery stuff exuded to spread thinly over the surface. He touched the stuff with his bare hand. It was uncannily different from snow, being infinitely more powdery yet dazzling white and deadly cold.
"You're witnessing the start of the Polar Cap's receding," Conley explained with a wry smile. "It does that twice a year, you know, getting smaller to about half its present size.
"Receding!" Jim exclaimed. "The damn stuff's expanding, you mean."
"It only looks that way. This is just the preliminary. Soon the extreme edges will vanish away and then the entire Cap will begin receding, for some strange reason. When that starts to happen, too bad for any man caught up here. Frankly, Jim, I should say that, if this continues tomorrow, we ought to head back."
That struck an ominous note in Jim's heart, but he said nothing. To return now would mean they must wait several months before making another attempt.