As related in the third book of this series, "The Boy Allies with the
Cossacks," Hal and Chester had seen active service under the Russian Bear
in the eastern theater of war. They fought in the midst of the Russian
forces and were among the troop of 60,000 that made the first wild dash
over the Carpathians to the plains of Hungary.

Returning to the western war area with despatches from the Grand Duke
Nicholas to the French commander-in-chief, they had again taken up their
duties with the British army. As related in "The Boy Allies in the
Trenches," they had been instrumental in defeating more than one German
coup, and it was through them, also, that a plot to assassinate President
Poincaré had failed.

Both lads were about the same age. Large and strong, they were proficient
in the use of their fists and of the art of swordsmanship, and were
entirely familiar with firearms. Another thing that stood them in good
stead was the fact that both spoke French and German fluently. Also, each
had a smattering of Italian.

Following their coup in saving the French president from the hands of
traitorous Apaches in Paris, Hal and Chester had come to Rome with their
mothers, whom they had found in Paris, and Chester's uncle. They had not
come without protest, for both had been eager to get back to the firing
line, but their mothers' entreaties had finally prevailed. As Chester's
Uncle John had said, "This is none of our war. Your place, boys, is with
your mothers."

Chester and Hal had sought consent to rejoin the army in vain. Neither
Mrs. Paine nor Mrs. Crawford would hear of such a thing. So at last they