thing on what we're going to tell you, Jimmy
Blazes!" cried Bob Dalton excitedly.

"Have we all won the _croix de guerre_?" asked Jimmy, smiling.

"No, but here's a note from the 'spy' we denounced," and Jimmy, as
he accepted a paper Bob held out, wondered at the happy looks on the
faces of his chums.

It was explained, however, when he read the note. A glance at the
signature told him it was from "Captain Frank Dickerson."

"Boys, you only did your duty in exposing me, as you thought you did,"
wrote the officer. "I congratulate you on your nerve, and on doing
what you so plainly disliked to do, after I had saved your lives, as I
may flatter myself I did.

"So don't worry about me. I was only doing my duty, too, for Uncle Sam
when I was within the German lines and in a German uniform. And I
was also doing my duty when I was within your lines in an American
uniform. My superior officers know all about it. That is all I can
say now, except to add that I was not under arrest very long. But that
action had to be taken to keep my plans from becoming known, even to
the major. I hope to meet you all again."

"Say, what does it all mean?" asked Jimmy, to whom so many things
had happened in the last few hours that it was no wonder he was a bit
dazed. "What's all this talk about the government knowing he was in
German uniform and all that?"

"Don't you understand?" inquired Bob, with a smile. "He was a spy."

"Of course he was a spy!" asserted Jimmy. "I sized that up all right.
He was a spy inside our lines and--"

"Yes, but he was also a spy inside the German lines," put in Roger.
"Don't you understand, Blazes! Captain Dickerson wore the German
uniform to get possession of some of their secrets. He's in the United
States Secret Service."

Jimmy looked first at one and then at the other of his chums, until he
had faced them all in turn.

"Gee!" he exclaimed at length. "What a chump I was not to guess that,
when he acted so coolly after I denounced him! What a chump I was!"

"Oh, well, we couldn't guess everything," said Franz, "And he
certainly acted suspiciously at times."

"Yes, so I dinks myself," agreed Iggy, who had not spoken for some
time.

"Well, it's all over--at least we've cleared up two mysteries,"
observed Bob. "I wonder what will happen next?"

"Well, there's going to be more fighting; that's sure," declared
Jimmy, "and I want to do my share!"

"Same here!" echoed his chums.

And whether they