“I don’t think so,” replied Hal.  “There are probably more French troops ahead of us.”

“I am sure I’m right,” persisted Chester.

“Well, it’s not worth while taking a chance,” said Hal.  “We’ll turn south here.”

At a cross road he swerved toward the south again.  But, although neither lad realized it then, they had penetrated right through the German lines where they had been thinnest and most greatly scattered.  They were still north of the Aisne, and the main German line lay between them and the far shore, where the French were massed in strength.  They could have turned west again at this point and probably have reached safety by the way they had come; but neither realized his danger, and so the big car sped south directly toward the enemy.

It was night now, and the machine was forced to travel more slowly, running along at a snail-like gait until the first signs of dawn appeared in the eastern sky.  An hour later the lads made out in the distance a mass of troops.  They were still too far away to make out plainly, but neither doubted that they were French.

But they were doomed to disappointment.

As the machine sped closer, Hal suddenly applied the brakes and uttered an exclamation of dismay.

“What’s the matter?” demanded Chester.

“Matter!” echoed Hal.  “Why, we have run right into a nest of Germans!”

It was only too true.  The troops whom they were now approaching were the enemy, and both lads realized in an instant that they must be surrounded by Germans on all sides.  In the darkness they had penetrated through the rear line, and now were in the very midst of their foes.

Hal thought quickly.  So far they had not been perceived.  Two men in civilian clothes were approaching afoot, and as they came up to them Hal crawled under the machine and began to tinker with it.  The men came closer and stopped to watch.

Suddenly Hal crawled from under the car, and, as the men cried out in surprise at the sight of his British uniform, he covered both of them with a pair of revolvers.

“Silence!” he cried, “or you are dead men.”  He spoke to Chester over his shoulder.  “We’ll have to go straight though the line,” he said, “and we can’t do it with these uniforms.  We’ll have to exchange with these fellows.”

In vain did their prisoners protest.  Hal kept the two covered while Chester stripped himself of his own garments and climbed into those one of the prisoners passed to him.  Then Chester covered the men while Hal made a change and transferred the document given him by General French to the pocket of his new coat.  Then they bound and gagged the two men and tumbled them into the ditch at the side of the road.

“So far so good,” said Hal.  “Now, if we simply act unconcerned, we should have no difficulty in going through the lines.  It’s when we make a dash for the other side that the trouble is likely to come; but we must chance that.”