Suddenly the concussion of a heavy gun shook the mill, making the old walls rattle and sending up little clouds of grain dust from nooks and crannies where it had gathered for many peaceful years.

“The Germans have surrounded us?” cried Roger.  “Do you mean that?”

“Look for yourself,” said Jimmy, and his very calmness as he pointed from the window seemed to indicate that he was master of himself.

His four companions looked as he indicated.  Rolling down from the hills, which surrounded the little valley in which the mill was located, were ranks of gray-clad men; Huns beyond a doubt.  And they were coming in force.

“Do you suppose they are after us?” asked Bob, and he was quite surprised when his four chums burst into laughter.  No, I am wrong.  Only three of them laughed—­Roger, Jimmy and Franz.  Iggy looked on almost as uncomprehendingly as did Bob, but Iggy was staring at a dead German on the floor of the mill—­a German he had killed by a bayonet thrust from behind, when that same German was about to fire his revolver, pointblank, at Roger.  Iggy was filled with many emotions as he looked at his work—­work undertaken and carried out for Liberty.

“What’s the matter?” asked Bob, a bit nettled.  “Doesn’t it look as though they were after us?”

“I don’t know why I laughed,” confessed Jimmy.  “Sort of nervous, I guess.  But the idea of a German army, or at least several divisions, coming to capture us five struck me as funny.”

“Well, you said we were being surrounded!” protested Bob.

“Well, I meant it, too.  But in a general way,” went on Jimmy.  “I don’t suppose the Huns know we are here.  Of course they may realize it after they find out we’ve silenced the machine guns.  But for the present this seems to be a big advance.  I guess there’s going to be some fierce fighting.  They’ve brought up some of their reserves to stop our progress, and by the fortunes of war, we’re caught in a back current.”

“You mean none of our fellows are here?” asked Roger.

“None that you can see,” went on Jimmy.  “I guess we sort of over-ran our objective.  There must have been a withdrawal and we didn’t know it.

“We were too intent on capturing this mill.  And we did, though it wasn’t easy.  And now the Germans are coming on, and—­well, if we can stay here long enough, and keep hidden, we may get out of it yet.  But—­”

He shrugged his shoulders.  It was too much of a question for him to solve.

“But I don’t see that we are completely surrounded,” declared Franz, hopefully, as he gazed from the window.

“Sure not!” broke in Iggy, who now began to comprehend, in a measure, what was in the wind.  “We may out run by der back door yet.”

“Not a chance,” declared Jimmy.  “Look over there!”