The letter
says that, after an investigation of our case, it has been decided that
we shall be sent back to Berlin and that, if we are to be allowed to
leave the country, such arrangements must be made by the United States
ambassador."

"Well, what do you think of that!"

"It's too bad," declared Fritz; "but an order is an order. I am afraid
you must go!"

"You poor boys!" exclaimed Frau Schmidt "I can't see why they won't let
you stay here."

"No more do I," declared Hal. "But I guess this letter means business."

"It sure looks like it," said Chester.

"That's what I call pretty tough luck," declared Hal, when the two boys
were alone in their room that night, Fritz and his mother having retired.

"Tough? I should say it is tough," returned Chester. "After all the
trouble we have had getting away from Berlin, then to have to go back.
Tough is no name for it."

"Well," said Hal, "I guess there is no use kicking. We ran a good race,
but we lost. It's back to Berlin for us."

Suddenly Chester sat bolt upright

"By George!" he exclaimed.

"What's the matter now?" asked Hal in surprise.

"I've an idea."

"Strange," replied Hal, with a smile; "but let's hear it."

"Well, in the first place, you took an airship ride to-day. How did
you like it?"

"Like it? Oh, I liked it all right. Why?"

"You saw Fritz work the thing. Did you get the hang of it?"

Hal jumped to his feet with a subdued exclamation.

"I see what you are getting at!" he declared. "An airship! Why didn't I
think of it myself?"

"There are only two objections I can see to the plan," said Chester.

"What are they?"

"Well, the first is, can you run the thing without spilling us out?"

"I am willing to take a chance if you are. Fritz explained the workings
of the machine while we were aloft to-day. I am sure I can do it. What is
the second reason?"

"The second reason is that it seems a shabby trick to play on Fritz,
particularly after the way he has treated us."

"So it does," agreed Hal slowly, but, after a pause, he added:
"However, I believe we had better do it. To me it looks like the
survival of the fittest."

For a long time the boys debated this point, but the matter was finally
settled when Hal said:

"Well, if we don't, we are likely to be stuck in Germany until the war is
over; and there is no telling when that will be."

"As long as we are going to do it, then," returned Chester, "the sooner
we start the better."