Both had distinguished themselves by their coolness and bravery under fire, and had found favor in the eyes of the Belgian commander, as related in “The Boy Allies at Liege.”  Later they had rendered themselves invaluable in carrying dispatches.

Following their adventures in this campaign they saw service with the British forces on the continent, as told in “The Boy Allies on the Firing Line.”  In this campaign they had been instrumental in foiling a well-planned German coup, which would have resulted in a severe blow to the British had it been put through.

Also, while scouting in the enemy’s domain, Hal and Chester had unearthed a conspiracy that threatened the destruction of a whole French army corps.  By prompt action the lads prevented this and won the congratulations of General Joffre, the French commander-in-chief.

It was through information gleaned by the lads that the British army was finally able to surprise the enemy and advance to the east shore of the River Marne, after a struggle that had lasted for two weeks.

In a battle following this decisive engagement—­while returning from a successful raid—­Captain Harry Anderson, who had accompanied them, was critically wounded and, together with Hal and Chester, taken prisoner.  Hal and Chester, with a French army dog they had rescued from the wrath of a German officer, were taken almost immediately to Berlin.

There, while strolling about the street one day in company with the German officer in whose charge they had been placed, they were made, to their surprise, the bearer of an important communication to the Russian commander-in-chief.  It happened in this wise: 

An English prisoner, recognizing them, made a dash for liberty and succeeded in passing the document to Chester.  The lad secreted it.  Finally, through their resourcefulness, the lads managed to make their escape from the German capital and reached the Russian lines by means of an airship.

Here they put the document into the hands of Grand Duke Nicholas, who, at their request, assigned them to a regiment of Cossacks.

The lads immediately made a good friend of a huge Cossack, Alexis Verhoff, a man of immense prowess and great strength, and with him saw a world of fighting.  In a battle with the enemy, Marquis, the dog who had accompanied them, was killed.  Later, while they were making their way back to England by airship, Alexis, who accompanied them, was wounded on the coast of Sweden, where their machine, crippled by the fire of German aviators, had fallen.

While Alexis stood off the foe the lads repaired the damage to the machine, but when they finally succeeded in dragging the huge Cossack aboard and once more headed toward home, they found that their friend was wounded unto death.  He died as the aeroplane sped over the North Sea.

In Russia both lads had been decorated with the Cross of St. George by the Czar of Russia himself—­this for their bravery and daring.