" the lieutenant assured them. "Both Joe and Frank
were upon the outside when we entered."

"But they would try to get us out," said Jerry. "If they were out there
they would give us some sort of signal that they were trying to help
us."

"We might not be able to hear them," answered the lieutenant, even
against his own judgment. "But look at it this way. Even though they
never were inside here, they had a fair idea of what the place was like.
They knew from that that we needed help, and needed it quickly. If one
went alone, and anything happened to him on the way, the other might
wait here indefinitely, not knowing whether he had got assistance or
not. By going together they took the safest course."

And Lieutenant Mackinson's reasoning was correct. That was exactly the
way Joe and Frank had figured it out, and, the latter forgetting all
about his own wound, they had started as fast as they could for the
American front.

"Keep cool, conserve your energy, and I feel certain everything will be
all right," the lieutenant told the two friends with whom, in such a
short time, he already had gone through so many harrowing experiences.

At that very same moment, a quarter of a mile away, Joe brought his
companion to a halt, took out his flashlight, and, facing the American
line, began making and breaking the connection in a way to give a number
of short, even flashes.

Presently a light appeared, was extinguished and appeared again, at the
edge of the American-French lines.

Joe had resorted to another sort of wireless--the "blinker"--and, not
knowing the call signal for the station he was nearest, had given the
prescribed call in such a case, a series of short flashes, or dots. The
station had acknowledged, and he began sending his message out of the
little battery in his hand:

"Americans. Three of party caught in cave-in. Need help."

And the answer was flashed back in the same code:

"Approach. Keep light on. Countersign."

Following these instructions, with Joe in the lead with the flashlight
held out in front of him, they dashed on to the trenches. They gasped
out the countersign, and were escorted by a sentry to the quarters of
the officer of that particular section.

In a few words they told him what had happened.

Without an instant's delay the latter, a colonel of artillery, reached
for his telephone.

"Ask Captain Hallowell to come here immediately," he said, and severed
the connection.

He seem