"Friends," returned Hal.
The sentinel recognized the lad's voice.
"Advance," he said with a breath of relief.
A moment later the boys were safe back among their own men.
"If the Germans had been as watchful as our own sentries, we would have had more trouble," said Hal.
"Oh, I don't know," was Chester's reply. "I saw a German sentinel, but he didn't see me in the darkness."
"It was his business to see, however," declared Hal.
"Well, that's true. But now let's listen and seen if we can overhear anything of importance."
Chester clapped the little receiver to his ear. Hal became silent.
Ten minutes later Chester removed the receiver from his ear.