He brought up abruptly at the bottom, and felt Hal’s hand upon his arm.

“Great Scott!” he ejaculated.  “Where are we?  Down in the bottomless pit?”

Hal clapped his hand over Chester’s mouth, for his keen ears had detected the sounds of footsteps above.

“Quiet!” he whispered.

Chester needed no second warning.  He did not move a muscle.  From above came the sound of a voice: 

“I wonder where they went?”

“I don’t know,” answered another voice, “but we had best be careful.  They are probably armed.”

Now, Hal, moving his position slightly, felt a space behind him, and crawled slowly backward, where the darkness seemed greater, pulling Chester along after him.  They continued this crawling for some minutes.  Finally, raising his head, Hal dropped quickly again with a muttered exclamation.

In arising his head had come in contact with something above him.  Raising an exploring hand, he investigated.  He touched a rock above.  Then he reached out on each side.  As he had surmised, only a few feet each way were solid walls.

“A cave,” he muttered.

“What?” asked Chester.

“We are cooped up in a cave.  If the Germans are wise enough, after they learn where we are, they will just sit down on the outside and starve us out.  But, if they try to come in—­well, I don’t think they will get very far, as long as our cartridges hold out.  You wait here until I see how far back this thing goes.”

Chester obeyed, and Hal continued his exploration.  For two or three minutes he crawled along, and then, turning a slight bend, gave a sudden exclamation.  He had come upon a possible means of exit, for, apparently, the cave had two openings.

Quickly Hal poked his head out and looked around.  He could see no one.  Slowly he crawled back to where he had left Chester, and informed him of what he had learned.

“Then the best thing we can do is to get out of here quick,” was Chester’s decision.  “Let’s go.”

Slowly Hal led the way along the low passageway, and, reaching the opening again, poked his head out.  This time he was doomed to a disappointment.  Hardly had his head emerged from the hole in the ground when he drew it in quickly again.

“What’s the matter now?” demanded Chester.

“Matter is,” said Hal quietly, “that there are six Germans standing about five yards from the entrance.”

“What!” cried Chester, in consternation.

“Exactly,” said Hal; “if you don’t believe it have a look for yourself.”

“Oh, I don’t want to look,” said Chester, bitterly disappointed.  “I can take your word for it.  What are we going to do now?”

“Well,” said Hal, “it looks to me like a good time to get out the other end.”

“Yes, but there are likely to be a few of them hanging about there, also,” said Chester.

“That’s so, too,” agreed Hal.  “Well, I’ll tell you what:  You sneak back there and investigate, and I’ll stay here and guard this end, in case one of them tries to get in.”