Hal heard a slight chuckle wafted over the wire.

"It shall be done," came the reply, and the military governor of Paris rang off.

Hal turned to Chester with a smile.

"I guess that will fix it," he said.

"Well, I should say so," said Chester. "But what will Uncle John and our mothers think when we are dragged away, apparently as prisoners?"

"I don't know what they'll think," said Hal, "but we are in honor bound to see this thing through, and we must not let sentiment stand in the way."

"I guess you are right," said Chester slowly, after a moment's hesitation.

"I know I am," said Hal, and so the matter rested.

It was nearly eight o'clock, as Hal perceived by a glance at his watch, when the heavy sound of tramping feet became audible in the hall.

"Room 257," came a voice from without.

There was a loud rap on the door.

"Who's there?" called Hal, thinking to keep up the deception.

"Open the door in the name of the law!" came back the response.

From an adjoining room Mrs. Paine, Mrs. Crawford and Uncle John were startled by the pounding on the door, and looked into the hall just as the above conversation through the door took place. Uncle John immediately stepped forward.

"What is the meaning of this?" he demanded.

The French officer turned upon him.

"None of your business," he replied. He turned and rapped on the door again. "Open the door," he commanded, "or I shall break it in."

"Hold on there!" said Uncle John. "I have the key to the door. Tell me what you want with those young men and I'll unlock the door."

"I am ordered to take them before General Gallieni at once," said the officer more civilly.

"The military governor!" exclaimed Uncle John.

"Exactly, _monsieur_," said the officer, "and now, as you have the key, will you please to unlock the door immediately?"

"But what does the general want with them?" asked Uncle John anxiously.

"I cannot say," was the reply. "Will you unlock the door or shall I be compelled to use force?"

Without further words Uncle John unlocked the door, and the officer, followed by two of his men, strode in. They approached the two lads.

"You are under arrest," said the officer briefly.

Mrs. Paine and Mrs. Crawford attempted to reach their sons, but the soldiers barred their progress.

"Don't worry, mother," said Hal, as they were led by, and he smiled.

Uncle John caught the smile and a great light dawned upon him.

"Well, by George!" he said to himself, "I didn't think they had it in 'em."

He allayed the fears of the anxious mothers by telling them what he had discovered.

CHAPTER XXII.

INTO THE UNDERWORLD.

Hal did not see the look of understanding upon Uncle John's face, as they were led along, but Chester did. He smiled to himself.

"Uncle John has caught on," he said to his friend.

"Caught on?" echoed Hal.

"Yes. He knows that we have hoodwinked him."

"So much the better, then," said Hal. "It will save our mothers some worry." He turned to the officer who conducted them as soon as they were out on the street. "It's all right now," he said. "We can go the rest of the way alone."

"Perhaps you can," was the reply, "but you won't. You'll come right along with us."

"But," protested the lad, "we must first go to our other hotel and get the clothes we have secured for our work."

"You will have to talk to General Gallieni about that," said the officer gruffly.

"But General Gallieni knows all about our plans."

"Does he? I'm not so sure. However, I guess he will before long?"

"Look here," said Hal, "what's the matter with you?"

"Come, now," said the officer, "that's enough of that. March."

Chester broke into a laugh, and Hal glanced at him in surprise.

"What are you laughing at?" he demanded.

"Why," said Chester, "I am laughing because you can't see through this."

"Is that so?" said Hal, somewhat nettled. "Perhaps you can see through it?"