ore had
flown alone, now was towing a glider--a glider that had arisen, as if
by magic, from the housetops!

Another instant and we had piled into the cockpit of the tri-motored
plane and were off on our pursuit. That pursuit that led us on and on
till, as the sun sank behind us, we found ourselves above the
illimitable, tawny wastes of the great Arabian Desert.

And now--what? All day long, as I have said, the plane we were
pursuing had maintained, but never increased, the distance between us.
Each hour had brought us renewed hope that the next hour would bring
capture--or at least some definite clue, some shred of information.
But the plane, still towing its glider, had gone on and on, steadily,
imperturbably. And we dared not open fire and attempt to bring it down
for fear of destroying our one meager chance of following it to its
destination.

* * * * *

And now it had vanished. Suddenly, unaccountably it had taken on that
terrific burst of speed which I have described. In ten minutes it had
become a speck on the far horizon--in another instant it was gone. We
were alone. Night was falling. If we turned back our gas might bring
us to safety. If we went on--what?

I turned to my companions. Foulet still maintained his non-committal
attitude, but Brice was deeply disappointed and worried. His ruddy
English face was knotted in a scowl and his blue eyes were dark.
Quickly he jerked his head back. We understood. Of course, turning
back was the only thing to do; to go on was absurd. Our quarry had
totally disappeared. But it was heart-breaking. Once again we had
been fooled and outwitted. Our disappointment filled that tiny cockpit
like a tangible mist. Brice threw over the stick with a gesture of
disgust. In response our right wing lifted a bit, seemed to shake
itself, then settled--and the plane continued on its course. Brice's
eyes flickered with surprise. He shoved the stick back, threw it over
again, but toward the opposite side. Obediently our left wing lifted
as if to bank, a shudder passed through it, it dropped, the plane
leveled, and went on.

Foulet leaned forward, his eyes were gleaming, his face flushed and
eager. "Climb!" he yelled above the roar of the motors. "Up!" Brice
nodded--but it was no use. That plane was like a live thing; nothing
we could do would swerve it from its course. We stared at one another.
Were we mad? Were we under a hypnotic spell? But our minds w