strange way. For when the rocks had been pulled down
sufficiently to enable them to crawl through, they emerged into a
space--a small room, as it were--walled with solid logs. Logs also
formed the roof. It was a room lighted by a lantern, and on a pile of
bags in one corner lay a huddled figure of a man. Standing near him was
another man--a man in a ragged blue uniform--and at the sight of his
face Blake murmured:

"Lieutenant Secor!"

"At your service!" said the Frenchman, bowing slightly.

"No!" bitterly cried Blake. "Not at _our_ service--you traitor!"

The Frenchman seemed to wince, but at that moment a call from the
huddled man in the corner attracted his attention. He bent over him,
drew back the covering and revealed in the lantern's glow the face of
Labenstein.

The German raised himself on one elbow, and a wild look came over his
face. His eyes gleamed brightly for a moment.

"They--they here!" he murmured. "Well, perhaps it is better so."

"How better? What does he mean?" asked Blake. "Does he think----"

"Hush!" and the Frenchman spoke softly. "This is the end--of
Labenstein!" And even as he spoke the man fell back dead.

Lieutenant Secor seemed to breathe a sigh of relief, as though the death
of the other had brought a great release to him.

"Now I can speak," said the officer. "Now I can explain, and perhaps you
will again regard me as a friend," he said softly.

"Well," returned Blake, "you probably saved our lives by helping us get
out of the tunnel. But as for being friends with----"

"Please do not say it," begged the lieutenant. "I have had to play a
part. It is over now. I can again take my place with my comrades and
fight openly for France. For I have learned all his secrets and whence
the spy-leaks came. Now my unpleasant mission is over!"

"What--what do you mean?" asked Joe, beginning, as did his chums, to
have an inkling of the truth. "Aren't you two working together against
us and for Germany?"

"Never I!" cried the Frenchman. "I am a member of the French Secret
Service, and for months I have consorted with that dog!" and he pointed
at the dead man. "I but played a part to gain his confidence and to
learn from what sources Germany was getting her secret information about
our soldiers and yours. Now I know. I will explain. But come, we must
get out of here."

"Can we get out?" asked Blake.

"Surely, yes. The tunnel goes from here into the German trenches, and
the other end wa