“Let us send for him at once!” exclaimed Uncle John.

Carg scribbled on a card.

“He wouldn’t leave the launch without orders, unless forced by the Germans,” asserted the captain, and handed the card to von Holtz.

The young lieutenant took his cap, bowed profoundly and left the room.  In ten minutes he returned, saying:  “I am not so fortunate as I had thought.  All our troops are on the move, headed for the Yser.  There will be fighting, presently, and—­I must remain here,” he added despondently.

“It won’t be your last chance, I’m sure,” said Patsy.  “Will that dreadful Colonel Grau go, too?”

“No; he is to remain.  But all regiments quartered here are now marching out and to-morrow a fresh brigade will enter Ostend.”

They were silent a time, until someone rapped upon the door.  Von Holtz admitted a slim, good-looking young Belgian who grasped his hand and said eagerly in French: 

“You sent for me?”

“Yes.  You may speak English here, Monsieur Rondel.”  Then he presented his friend to the Americans, who approved him on sight.

Henderson came a few minutes later and listened respectfully to the plan Miss Doyle unfolded.  He was to go with Monsieur Rondel to Charleroi, find Mrs. Denton, explain that her husband was very ill, and bring her back with him to Ostend.  He would report promptly on his return and they would tell him what to do next.

The man accepted the mission without a word of protest.  Charleroi was in central Belgium, but that did not mean many miles away and Rondel assured him they would meet with no difficulties.  The trains were reserved for soldiers, but the Belgian had an automobile and a German permit to drive it.  The roads were excellent.

“Now, remember,” said Patsy, “the lady you are going for is Mrs. Albert Denton.  She lives with her mother, or did, the last we heard of her.”

“And her mother’s name and address?” inquired Henderson.

“We are ignorant of either,” she confessed; “but it’s not a very big town and I’m sure you’ll easily find her.”

“I know the place well,” said Rondel, “and I have friends residing there who will give me information.”

Uncle John supplied them liberally with money, impressed upon them the necessity of haste, and sent them away.  Rondel declared the night time was best for the trip and promised to be on the way within the hour, and in Charleroi by next morning.

Notwithstanding the fact that they had succeeded in promoting by proxy the mission which had brought them to Belgium, the Americans found the next day an exceedingly irksome one.  In the company of Lieutenant von Holtz they were permitted to walk about the city, but they found little pleasure in that, owing to the bustle of outgoing troops and the arrival of others to replace them.  Nor did they care to stray far from their quarters, for fear the council would meet and they might be sent for.