“No use,” sighed Freegift. “We may be losin’ time; like as not losin’ the doctor. Our orders were, to travel by river till we joined the cap’n.”

With one last survey the two men took up their tow-ropes and, Stub ready to lend a hand when needed, they plodded on.

The tracks of the doctor and John Brown led to the gateway before. The space for the river lessened rapidly. Soon the sides were only prodigious cliffs, straight up and down where they faced upon the river, and hung with gigantic icicles and sheeted with ice masses. The river had dashed from one side to the other, so that the boulders were now spattered with frozen spray.

The tracks of the doctor and John Brown had vanished; being free of foot, they might clamber as they thought best. But the sledges made a different proposition. Sometimes, in the more difficult spots amidst ice, rocks and water, two men and a boy scarcely could budge one.

Higher and higher towered the cliffs, reddish where bare, and streaked with motionless waterfalls. The sky was only a seam. Far aloft, there was sunshine, and the snow even dripped; but down in here all was shade and cold. One’s voice sounded hollow, and echoes answered mockingly.

The dusk commenced to gather before the shine had left the world above. Stub was just about tired out; the sweat had frozen on the clothes of the two men, and their beards also were stiff with frost.

Now they had come to a stopping-place. There was space for only the river. It was crowded so closely and piled upon itself so deeply, and was obliged to flow so swiftly that no ice had formed upon it beyond its very edges. The cliffs rose abruptly on either side, not a pebble-toss apart, leaving no footway.

The trail had ended.

“I cry ‘Enough,’” Terry panted, as the three peered dismayed. “We can’t go on—and we can’t spend the night here, either. We’ll have to backtrack and find some way out.”