u'll call it," answered Tom. "But
something has to be done."

"Yes, something has to be done," agreed Jack. "Now what is it?"

Tom arose and went to the door. He opened it, looked carefully up and
down the hall, evidently to make sure no one was listening, and then
came back to join the circle of his friends.

"I'm going to speak of something that very few know, as yet," he said,
"and I don't want to take any chances of its getting out. There may
be German spies in Paris, though I guess by this time they're few and
scattering.

"I'm not going to tell you how I know," he said, "but I do know that
soon there is to take place a big battle--that is, it will be big
for the American forces that are to have part in it. There has been a
conference among the Allied commanders, and it has been decided that
it's time to teach the Germans a lesson. They've been despising the
American troops, as they despised General French's 'contemptible little
army,' and General Pershing is going to show Fritz that we have a
soldier or two that can fight."

"You mean there's to be a big offensive?" asked Jack.

"No, I wouldn't go so far as to call it a general engagement like that.
It's to be kept within the limits, of the sector where the United States
troops are at present," said Tom. "That is where you and I are located,
Jack, and that, as you know, is almost opposite the prison where Harry
and the others are confined."

"I begin to see what you are driving at!" cried Nellie, her eyes
shining. "But are you sure of this?"

"Yes," went on Jack, "how did you bear of this when it's supposed to be
such a secret?"

"It came to me by accident," said Torn, "and I wouldn't speak of it to
any one but you. Soon, however, it will be more or less public on our
side, as it will have to be when we start to get ready. But it's to
be kept a secret from Fritz as long as possible. It's to be a surprise
attack, and if it doesn't develop into a big battle it won't be the
fault of Uncle Sam's boys."

"Will the air service have any part in it?" asked Jack eagerly, as if
fearing he might be left out.

"I don't see how they can get along without us," said Tom. "Not that
we're the whole works, but it is well established now that an army can't
fight without the use of aeroplanes, to tell not only what the other
side is doing, but also how our own guns are shooting. Oh, we'll be in
it all right!"

"When?" asked Jack.

"That I can't say," replied his chu