ven before he had finished the sentence the aviator had taken up the partially obliterated trail of spattered blood drops. That what he sought appeared to be a maraudering party of giants restrained him not at all. The one clear thought burning in his weary brain was that Richard Alden, his best friend—the man with whom he had traveled over half the world, by whose side he had faced many a perilous situation—must at that moment lie in peril, the extent of which he could only surmise.
"Must have been about a dozen of them," he said thickly. And, holding the Winchester ready, he commenced once more to plod on through the stinging sheets of wind-driven ice particles. More than once he had great difficulty in not losing that crimson trail, for here and there the restless, white crystals completely blotted out the splashes.
All at once Nelson checked his pathetically slow progress, finding himself on the top of an eminence, looking down in what appeared to be a vastly deep natural amphitheater of snow and ice. At the bottom, and perhaps a hundred yards distant, was a curious black oval from which appeared to rise a dense, wind-whipped column of whitish vapor.
"My eyes must be going back on me," muttered Nelson through stiffened lips. How intolerably heavy his fur suit seemed! His strength was about gone and that curious black mouthlike circle seemed infinitely far away. But, spurred by fears for his friend, he started downward for the precipitious trail leading directly towards it.
Once he stepped inside the crater, he became conscious of a terrific side pressure which gripped him as a whirlpool seizes a luckless swimmer. The wind buffetted him from all angles, dealing him powerful blows on face and body, which, too strong for his weary body, sent him reeling weakly, drunkenly across the hard, glare ice towards the vortex. Twice he slipped, each time finding it harder to arise. But at last he approached what on closer inspection proved to be a subterranean vent of black rock.
"Steam!" he gasped. "It's steam coming out of there!"
