The officer stopped him with an imperious gesture.  He looked rather stern, and then, as though conscious that this was not the attitude to take, he smiled.

“I’m glad I was able to serve you,” he said.  “I happened to be in the neighborhood.  I heard your cries after the mill collapsed and began to burn, and I hastened up.  I had no time to summon help—­in fact, your friends are rather distant from here now.  The Germans are all about.”

“We know it—­to our sorrow,” replied Bob.  “How we are going to get back to our company is what’s worrying me.”

“It is going to be a problem,” assented the officer.

“Are you coming with us?” asked Jimmy.  It was a perfectly natural question.  Here was one—­by most appearances an American officer—­marooned with some American doughboys in the midst of the Germans.  Why should he not cast his lot with them, and lead them to the best of his ability to the safest place?  He was an officer—­there was no question of that—­and it was his right to lead.  But he seemed disturbed at Jimmy’s question.  He looked searchingly at the boys, and then toward the distant hills where the Germans were massed, though not then in sight.

“No, I—­I can’t come with you,” the unknown said.  “I’m sorry, but you will have to shift for yourselves.  I’ll give you the best directions I can to enable you to reach your own lines, but you’ll have to go alone.”

“We’ll try,” said Bob.  “But we wish to thank you, and we don’t know—­”

“Oh, it was all in the day’s work,” interrupted the officer, “Any one who came along would have done just as I did to help you.”

“Not anyone, sir,” asserted Franz, in a low voice.  “A German wouldn’t have chopped us out.”

“Well—­er—­perhaps not,” said the officer.  “But it was in my line of duty and I did it.  I don’t want to be thanked for doing my duty.”

“But we insist on thanking you, sir!” exclaimed Jimmy with a smile.  “If it hadn’t been for you we’d be dead in there now—­it was impossible for us to free ourselves!”

“Well, you may call me Captain Frank Dickerson,” said the officer slowly.  And he appeared to hesitate over the words.

“Then allow me, in the names of my companions, to thank you from the bottoms of our hearts!” exclaimed Jimmy, rising and saluting.  The captain returned the salute.  He stood for a minute looking Jimmy straight in the eyes, and the lad said afterward that the officer seemed to be searching out the sergeant’s very soul.  Then Captain Dickerson said: 

“I must leave you now.  You will find a little package of food at the end of the mill flume.  I’ll leave you this canteen so you may carry water with you on your journey toward your own lines.  Your way lies there,” and he pointed to the south.  “Good-bye—­and good luck!  I hope you may get through, but—­”

Then, turning abruptly he strode off between two high grassy hummocks, and was soon lost to sight in the smoke and haze.