ey learn will avail them naught for we can
warn the French commander later. We must find out what they are up to.
We'll stick close and follow them back to the German lines, if
necessary."

"Good, then! Guess we had better do a little skirmishing about. It will
keep suspicion from us should we be watched."

"All right," said Frank. "Come on."

CHAPTER VIII

A STARTLING DISCOVERY

With the coming of midnight Frank and Jack returned to the spot where
the aeroplanes had been parked. Several of the German aviators already
had returned. The man who appeared to be the leader announced that they
would await the arrival of the others before taking to the air.

The others arrived one at a time until all were present but two. The
machines were in readiness to ascend the moment the missing men
arrived. The aviators were at their posts.

Suddenly there came a shout. A moment later the two German aviators who
were delaying the departure burst into sight at a dead run.

"Quick!" called one. "We are discovered!"

Immediately the others--Frank and Jack among them--leaped into their
machines and soared into the air. The last comers also leaped for their
craft and succeeded in getting above ground just as rifles began to
crack in the French camp.

Came a sudden cry from the machine nearest that of Frank and Jack. The
lads saw a man rise to his feet, throw up his arms and pitch, head
foremost, toward the ground. The aircraft, freed of a guiding hand,
rocked a moment crazily and then turned over, hurling its other
occupant into space.

There was a cry of anger from aboard some of the other German craft,
but no man raised a hand to stay the flight of his car. It would have
been suicide and the Germans realized it. They sped away into the
darkness whence they had come. Frank and Jack, in their British
hydroplane, went with them.

For an hour or two the aeroplanes sped through the darkness at
undiminished speed; then the foremost craft slowed down. The others did
likewise.

"Surely we haven't reached the German lines already?" said Jack. Frank
shrugged his shoulders.

"You know about as much of what is going on as I do," he returned.
"Evidently we are going down, however."

The lad was right.

The leading German plane swooped toward the earth and the others
followed its example. A few minutes later all had reached the ground
safely and their occupants had alighted.

The two lads glanced around. It was very dark.