murmured Percy to himself.

He had no theory--no suggestion. Yet the matter seemed an ominous one.
It was unheard of that an encounter with a hundred volors should take
place, and he wondered why they were going southwards. Again the name of
Felsenburgh came to his mind. What if that sinister man were still
somewhere overhead?

"Eminence," began the old man again. But at that instant the car began
to move.

A bell clanged, a vibration tingled underfoot, and then, soft as a
flake of snow, the great ship began to rise, its movement perceptible
only by the sudden drop and vanishing of the spire of rock at which
Percy still stared. 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.... Whatever it was, was behind them now, vanished into
the thick night.

There was a sound of talking from the interior of the car, hasty,
breathless voices, questioning, exclaiming, and the authoritative terse
answer of the guard. A step came along outside, and Percy sprang to meet
it, but, as he laid his hand on the door, it was pushed from without,
and to his astonishment the English guard came straight through, closing
it behind him.

He stood there, looking strangely at the f