game--for how long Tom could only guess, and he seemed to feel cold
fingers clutching at his heart when he thought of this.

But Tom soon discovered, by a backward glance over his shoulder now and
then, that his machine, barring accidents, would distance the other, and
this was what his aim now was. So on and on he sped, watching the German
occupied French territory unrolling itself below him, coming nearer and
nearer each minute to his own lines and safety.

Behind them, he and Jack--for the latter had done his share before being
wounded--had left consternation in the German ranks. The bombs had done
considerable damage--as was learned later--and the dropping of packages
within the prison camp was fraught with potential danger to an extent at
which the Boches could only guess.

On and on sped Tom, sparing time, now and then, to look back at his
pursuers, who were, it could not be doubted, doing their best to get
within effective range. And, every now and again, Tom would glance at
the motionless form of his churn.

But poor Jack never stirred, and Tom was fearing more and more that his
chum had made his last flight. As for the Hun aviators, after using up
a drum or so of bullets uselessly, they ceased firing and urged their
machine on to the uttermost.

But Tom had the start of them, and he was also on a higher level, so
that the Germans must climb at an oblique angle to reach him.

And, thanks to this, Tom saw that, if nothing else happened, he would
soon be in comparative safety with the unconscious form of Jack. The
anti-aircraft batteries were firing in vain, as he was beyond their
range, and, far away, he could see the lines of the French armies,
behind which he soon hoped to be.

And then the unexpected happened, or, rather, it had taken place some
time since, but it was only then brought to Tom's attention. His engine
began missing, and when he sought for a cause he speedily found it.
Nearly all the gasoline had leaked out of the main tank. As he knew
that there had been plenty for the return flight, there was but one
explanation of this. A Hun bullet had pierced the petrol reservoir,
letting the precious fluid leak away.

"Now if the auxiliary tank has any in it, I'm fairly all right," thought
Tom. "If it hasn't, I'm all in."

His worst fears were confirmed, for the auxiliary tank had suffered a
like fate with the main one. Both were pierced. There were only a few
drops left, besides those even then