Chester stepped back with an exclamation of relief and Hal dragged himself from beneath his now unconscious adversary.

"A tough customer, that fellow," he remarked.

"You'd have done for him if you hadn't been so weak," Chester replied. "I didn't think we might have callers down here."

"Neither did I," returned Hal, "but I'm glad they came."

"Why?" demanded Chester in surprise.

"We can borrow their uniforms if it's necessary," Hal explained.

"By Jove! I hadn't thought of that," exclaimed Chester. "A good plan."

"Of course it may not be necessary," said Hal. "If the Germans should be driven back it would be unnecessary. We'll wait until after dark and see."

"In the meantime we had better tie these fellows up," said Chester. "One of them is coming to now. He may not know when he's properly licked and want to continue the fight."

"Better gag 'em, too," said Hal. "I noticed that one fellow had pretty good lungs."

The lads removed their belts and with these bound the hands of their captives. They had nothing to tie their legs, but they didn't feel there was much danger of the men crawling out of the pit with their arms bound.

They gagged them with their handkerchiefs.

A few moments later one of the Germans staggered to his feet and gazed at the two lads in astonishment. The second also soon regained consciousness and apparently was no less surprised. Both lads kept their revolvers handy, for they weren't sure whether the Germans might not attack them, bound and gagged as they were.

Hal addressed them.

"We expect to keep you company for some time," he said, "and we don't want any foolishness. The first false move will be your last. Get over there in the corner."

The men obeyed, growling to themselves.

Hal and Chester listened for sounds above that would indicate the retreat of the Germans and the advance of the French. No such sounds came; and with the fall of darkness Hal said:

"Well, I guess we had better change clothes with these fellows and make a break for it."

"Good!" agreed Chester. "We'll have to unbind them while they disrobe.

We'll strip one at a time. You hold the gun while I do the work."

"Well, I guess everything is all ready," said Chester, when they were at last garbed in the German uniforms and the men were safely tied up again.

"We may as well be moving."

"All right," said Hal, "climb up on my shoulders. I'll keep my gun on these two fellows in the meantime. Can't trust 'em."

Chester followed Hal's instructions and a moment later gazed out of the pit. Ahead he could see moving forms, but there was no one close to the pit.

"Coast clear," he called to Hal. "Here I go. Be ready when I reach down for you."

He pulled himself up.

CHAPTER XI

THROUGH THE LINES

"Ready, Hal?"

"All ready."

Hal stretched up his hands, and Chester, leaning far over the pit, seized them and pulled. Hal came slowly upwards.

Suddenly he gave a cry of pain and twisted and squirmed vigorously.

Chester became alarmed.

"What's the matter?" he asked quickly.

"One of those fellows bit me in the leg!" exclaimed Hal.

It was true.

As Hal had soared upward, one of the Germans had sprung forward, and being unable to free his hands, had seized the fleshy part of Hal's leg between his teeth. Evidently the gag had not been properly adjusted.

"Kick him loose!" cried Chester.

Hal obeyed instructions. The German uttered a loud cry--another sign that the lads had gagged him too carelessly.

In kicking out at the German, Hal had used too much violence and had jerked loose from Chester's hold. Down into the pit he plunged again.

Apparently believing that Hal had come back with the intention of silencing him forever, the ungagged German gave vent to a series of loud cries.

"Quick, Chester!" called Hal. "Pull me out of here before this fellow brings down the whole German army."

Chester leaned over and again seized Hal by the hands and pulled. Once more the German below sprang forward and attempted to sink his teeth in Hal's leg. Hal, realizing what the man was about, kicked out suddenly before the German could obtain his hold, and the lad's heavy shoe caught the man squarely in the mouth. One more cry the German gave and then toppled over.

"Quick Chester!" cried Hal, again.

With an effort Chester dragged Hal from the pit.

Hal stood up and both lads dusted the dirt from their clothes.

"Now the sooner we get away from this spot the better," said Chester.

They advanced directly west toward the extreme German front.

"We'll have to depend on boldness to take us through," said Hal. "It is unlikely that we shall be questioned until we reach the outposts and then we'll have to make a break for it."

"Suits me," said Chester.