"Well—here goes!"
Phi scrambled to the surface of a gliding cake, then, having raced across its surface, leaped a narrow chasm, to race on again. Such an obstacle race had never before been entered into by a boy and a dog. Rover, seeming to have regained some of the spirit of his younger days, followed well. Once, with a dismal howl, he fell into a crevice, but before an ice-pan could rear up and crush him, a strong arm dragged him free.
They had made two-thirds of the distance when, on a broad pan that shuddered as if torn by an earthquake, Phi paused. One glance at the rocky coast brought a sharp exclamation to his lips.
"It's like the wall of a prison," he muttered; "straight up.
"No," he whispered a moment later, "there's a bare chance—that rocky shelf. But it's fifteen feet above the ice, and how's one to reach it? There may be a way. One can but try."
They were off again. Each fresh escape brought them face to face with new and more startling dangers. Here they were lifted in air, to leap away just in time from a crash. Here they crossed a pile of crushed and slivered fragments only to face a dark and yawning pool of salt water waiting to sting them into insensibility. But always there was a way out. Each moment brought them closer to the frowning wall.
A last, close-up survey told the boy that there was no path, no slanting incline, no rugged steps to the shelf above. But from the shelf upward there appeared to be a possible ascent.
At that moment he saw something that made him catch his breath hard. A gigantic ice-pan, measuring hundreds of feet from side to side, had begun to glide upward over a mass of broken fragments toward that cliff.
"It will go as high as the shelf if it hasn't too many seams," he said aloud. "It may go up. And it may crash. But it's our only chance."
He looked at the dog. That the old fellow could make this perilous trip, could mount himself on the very edge of a giant, tilting cake of ice and ride up—up—up, inch by inch and foot by foot, to pause there a breathless distance in mid-air and then at the one critical second, leap to safety on the rocky shelf, the boy did not dream for a moment. Yet he had no thought of leaving Rover behind.