Slowly the snowfield too began to flit downwards, a black cleft, whisked smoothly into sight from above, and disappeared again below, and a moment later once more the car seemed poised in white space as it climbed the slope of air down which it had dropped just now.
Again the wind-chord rent the atmosphere; and this time the answer was as faint and distant as a cry from another world.

The speed quickened, and the steady throb of the screw began to replace the swaying motion of the wings.

Again came the hoot, wild and echoing through the barren wilderness of rock walls beneath, and again with a sudden impulse the car soared.

It was going in great circles now, cautious as a cat, climbing, climbing, punctuating the ascent with cry after cry, searching the blind air for dangers.

Once again a vast white slope came into sight, illuminated by the glare from the windows, sinking ever more and more swiftly, receding and approaching--until for one instant a jagged line of rocks grinned like teeth through the mist, dropped away and vanished, and with a clash of bells, and a last scream of warning, the throb of the screw passed from a whirr to a rising note, and the note to stillness, as the huge ship, clear at last of the frontier peaks, shook out her wings steady once more, and set out for her humming flight through space....