wished to overhaul the motor that was acting so badly.

The minutes dragged.

Then once more Jack bent his head, and put a hand up to his ear to
listen. He laughed to himself with glee.

"That's Tom coming!" he muttered joyously. "I knew Tom wouldn't fail me.
All the same I'll be mighty glad when I'm aboard the plane and on the
air route to Bar-le-Duc and my own cot."

Louder grew the sounds. There could not be the slightest doubt about it
now, Jack decided. A plane was coming at top speed, and keeping not a
great distance above the treetops of the little valley in which the
house of Carl Potzfeldt and the road to Metz lay.

Louder grew the insistent drumming. Jack wondered whether some of those
at the chateau might not also hear the racket, and, guessing what it
would mean, hasten out to the field in time to give Tom and himself a
volley of shots.

Now the plane was coming, like a great condor of the Andes about to
alight on a mountain peak. Jack gauged full well where it would land. He
ran with all his might to be close to the spot. The less time wasted in
getting him aboard the better for their safety, he believed, remembering
what cause Carl Potzfeldt now had for being suspicious when a plane
visited his meadow.

Then the big Caudron ran along the ground and came to a full stop.

"Jack!"

"Yes, Tom, I'm here, and mighty glad to see you!" cried the lad who had
counted the minutes until his brain seemed to reel with the strain.

"Get aboard in a hurry, Jack. We've no time to waste here."

"I know that even better than you do," returned the other.

There was indeed need of haste. The air service boys could hear voices
from where the chateau was located. Someone had heard the humming of the
oncoming airplane. It was Potzfeldt himself, and now he and two of his
men came hurrying out on the field, all armed with pistols.

Jack only waited to give the propellers a whirl, and then, as the motor
took up its work, he made a leap for his seat. Oh, how good it seemed to
be once more in that airplane!

"Stop! Stop!" roared a guttural voice in German. "Stop, or we fire!"

Now the airplane was moving along the ground, bumping and rocking
considerably. But Tom knew how to manage, and presently the plane
commenced to soar slowly upward.

Loud and angry voices announced the fact that Carl Potzfeldt had arrived
close enough to get a view of the rising plane in the misty light of the
moon.

"Stop! I command you! St