Fighting every inch of the way, the Belgian cavalry continued its retreat, being hard pressed by the Germans, who were continually reinforced.  From the rear the firing became heavier, and then there was heard the sound of a galloping body of horsemen.

“Halt!” cried the Belgian officer in command, and the retreating horsemen came to a stand.

“About face!” And at the command they wheeled to meet the charge of a force of Uhlans.

The Germans came on bravely; but, just as they hurled themselves upon their foe, there came from the Belgian rear a fierce hail of rifle shots.  Reinforcements had arrived.

The Germans halted in their fierce charge, and then drew off, shooting as they went.  At the same instant a regiment of Belgian infantry rushed forward on the run.  They pursued the flying Germans for some distance, and then turned back.

Then the Belgians resumed their retreat to their own lines.

Hal and Chester bore up bravely during this—­their first time—­under fire.  Unable to take part in the fighting themselves, being without weapons, they watched with interest the maneuvers of the officers and the gallantry with which the Belgian cavalry stood up against what at first were plainly overwhelming odds.

Once in the Belgian lines the boys breathed easier.

“Well, here we are at last,” said Hal.  “I guess we will be able to explain our presence in the woods satisfactorily.”

“I hope so,” replied Chester.

At this moment the officer who had placed them under arrest approached.

“Come with me,” he ordered.

The boys accompanied him to the headquarters of the commanding officer, where their position was explained to the latter.

He listened quietly to Hal’s account of their adventures since leaving Berlin, and it was plain to both boys that as he listened he became more and more incredulous.

Hal finished his recital, and for some minutes the general sat silent.  Finally he said: 

“You have told me a strange story—­one that I find it very hard to believe.  I must have proof.  It must be substantiated.  You will consider yourselves prisoners until the matter has been investigated, unless in the meantime there should be someone here who will vouch for your honesty and the truth of this remarkable tale.”

“I will vouch for it, general,” came a voice.

Turning, the boys beheld in the entrance to the general’s hut the smiling face of Captain Raoul Derevaux.

CHAPTER XII.

Liege.

Hal and Chester started forward.

“Captain Derevaux!” they exclaimed simultaneously.

The gallant captain smiled.

“Even so,” he returned.  Then turning to the general:  “I will vouch for the truth of the story told by these boys, sir,” he said.

“You know them, then?” questioned the general.