The third volume, called “The Khaki Boys at the Front,” tells in detail some of their exciting experiences.  The quintette were given leave to go from their camp to Paris, and in that beautiful city they met some other friends, the Twinkle Twins, otherwise John and Gerald Twinkleton, who had joined the aviation branch of the service.  This was natural, since their cousin, Emile Voissard, was one of the most daring of the airmen, meriting the name “Flying Terror of France.”

In that book, too, you may read of how Franz Schnitzel, by his knowledge of the German tongue, was able to give advance notice of a raid he overheard the Huns planning.  The raid was a failure from the German standpoint, but during it some of our Khaki Boys were wounded.

Adventure followed adventure, but in one “grand” one, as a Frenchman would call it, Jimmy, on guard when Voissard’s aeroplane was on the ground, temporarily disabled, stood off an attack of Germans and among others he killed Adolph von Kreitzen, known as the “tiger man.”  On his head the French government had set a price of five thousand francs, or about a thousand dollars, and of course Jimmy won this.

So now, in the opening of this present story, we find our five Khaki Boys still together after many strenuous happenings.  They had been wounded but were now recovered and they had fought valiantly.

In the last chapter of the book immediately preceding this, if you recall, the lads had written letters home—­letters which might be their last, they thought, for they had orders to take their places in the front line trenches to await the zero hour.  Two of the Brothers had been separated from their chums, but all were reunited as we have seen.

Then had come the command to go over the top, and there had followed the fierce rush in the gray dawn of the morning—­a rush punctuated by fire, smoke and death.

“Dig in!  Dig in!” commanded the lieutenant in command of the particular squad of the 509th infantry to which our friends were attached.  “This is only a temporary check.  We’re laying down a curtain of fire, and we’ll go forward again in a moment!”

He had to yell to be heard above the din, but all near him understood what he meant.  The American gunners were sending over a barrage fire—­a veritable rain of bullets that would keep the Germans from advancing, and which would also cause them to abandon their machine-guns.  It was the machine-gun fire that was, temporarily, holding up the advance of Jimmy and his chums.

It did not take the Sammies long, working feverishly as they did, to raise a protecting mound of earth between them and the Huns.  And then, for some reason or other, the savage fire of the Germans slacked at the particular section of the line where our heroes were stationed.

“Are you all right, Rodge?” called Jimmy to the chum on his left.

“So far, yes.  How about you?”

“Oh, I was nicked in one ear—­just a scratch.  It’s hardly bleeding.  Can you see Bob?”