wishing to be ready for any emergency.

Of course, it was immediately manifest to the officer that these three
wideawake lads were not of the enemy. Like most other people he at first
suspected them to be English boys. That would mean they were allies of
the French; but nevertheless those splendid wheels were a great
temptation; and the Grand Army was in sore need of all such means of
rapid locomotion it could commandeer.

"You are English, then?" he asked, politely, returning Rod's salute.

"No, American, monsieur," replied the boy, promptly; "we were making a
trip down the Rhine on our motorcycles when the war broke out. We had
just managed to get across the line into poor Belgium when the Germans
came. You can well understand that we have seen much of what happened in
that unfortunate country, for we were compelled to go to Antwerp on
business."

"But--this is France," interrupted the lieutenant, as though puzzled;
"and here close to the firing line it is peculiar that we find three
American boys mounted on such wonderfully fine motorcycles."

Rod smiled blandly.

"You wonder how we managed to retain possession of them through it all,"
he went on to say; "but the secret lay in a certain magical paper which
we carry, and which you shall yourself be permitted to examine."

With that he once more carefully extracted the document given to them by
the brave king of the Belgians, and which had proved to be worth a
thousand times its weight in gold.

So the French lieutenant, by the light of the flickering lanterns, also
read the brief but forceful sentences penned by King Albert. He was of
course greatly impressed, as who would not have been, remembering what a
prominent figure the royal writer of the "pass" had already become in
the world war?

"It is plain to be seen, young monsieur," the officer hastened to say as
he very carefully folded the precious paper, and with a bow returned it
to the owner, "that you and your brave companions have found occasion to
lend a helping hand to the grand cause for which all loyal Frenchmen are
ready to shed their last drop of blood. But I notice that here the
writer speaks of _five_ young Americans, and I see but three."

"That is easily explained," replied Rod; "two of our chums were
compelled to return hastily to America, having received a cable message.
They sailed from Antwerp for London, and by now are far on the way
across the Atlantic."

"But what possessed you th