We're to go to Paris to see them. They'll tell us all about it then."

"But what has that to do with our going over the Rhine?"

"Nothing. We're to go to Paris for a rest, and to get in shape for a big effort against the Germans. I'll tell you about it."

"Forge ahead, then."

Tom got up to look at the doors and windows of the French cottage back of the lines, where Jack had been moved to complete his recovery. Tom and Jack, after the sensational raid, had been given leave of absence.

"I just want to make sure no one hears what I say, for it's a dead secret yet," Tom went on. "But this is the plan. The French have several of the biggest and newest Italian planes--planes that can carry half a dozen men and lots of ammunition. Our aerodrome is going to be shifted to the Alsace-Lorraine front, and from there, where the distance to German territory is shorter than from here, we are to go over the Rhine and bombard some of their ammunition and arms factories, and also railroad centers, if we can reach 'em."

"Good!" cried Jack. "I'm with you from the fall of the hat!"

"First you've got to build up a little," stated Tom. "There is no great rush about this Rhine-crossing expedition. A lot of plans have to be perfected, and we've got to try out the Italian plane. And, before that, we are to go to Paris."

"Who says so?"

"Major de Trouville. He's greatly pleased with the result of the raid on the big German guns, and says we're ent.i.tled to a vacation. Also he knows I want to make some more inquiries about my father. But I fear they will be useless," and Tom sighed.

"And are we to go to see Mrs. Gleason?" asked Jack.

"Yes. And Bessie, too. They'll tell us all that happened."

A few days later, having received the necessary papers, Tom and Jack were once more on their way to the capital. And this time they did not, with others, have to suffer the danger and annoyance of the long-range bombardment. It was over for a time, but there was no guarantee that the Germans would not renew it as soon as they could repair the damage done to their giant cannons.

The boys found Bessie and her mother in lodgings in a quiet part of Paris, and were met with warm greetings. Then the Gleasons told their story.

They had been inveigled out of their lodgings by the false note from the boys, and had immediately been taken in charge by the spy, who, it was proved, was an agent of the infamous Potzfeldt. But Bessie, after several days' captivity in an obscure part of the great city, managed to drop a letter out of the window, asking for help.

The police were communicated with, and not only rescued Mrs. Gleason and her daughter, but caught the spy as well, and secured with him papers which enabled a number of Germany's ruthless secret service agents to be arrested.

It was because of the necessity for keeping this part of the work quiet that no word of the rescue of Bessie and her mother was sent to the boys until after the big gun raid.

There was much to be talked about when the friends met once more, and Mrs. Gleason said she and Bessie were going back to the United States as soon as they could, to get beyond the power of Potzfeldt.

As Tom had feared, there was no news of his father, but he did not yet give up all hope.

"If he's a prisoner there's a chance to rescue him," he said.

The time spent in Paris seemed all too short, and it came to an end sooner than the boys wished. Jack was almost himself again, though he limped slightly from one of the German bullets in his leg. There was every hope, however, that this would pa.s.s away in time.

Good-byes were said to Bessie and her mother, and once more the two Air Service boys reported to their aerodrome. There they found not one, but two, of the big Italian machines, which are capable of long flight, carrying loads that even the most ponderous bombing plane would be unable to rise with.

Preparations for the bold dash into the enemy's country went on steadily and swiftly. Tom and Jack were trained in the management of the big birds of the air, and though it was essentially different from what they had been used to in the Nieuports and the Caudrons, they soon mastered the knack of it, and became among the most expert.

"I believe I made no mistake when I picked them to be part of the raiding force," said Major de Trouville.

"Indeed you did not," agreed Lieutenant Laigney. "Their work in discovering the big guns, and their help in silencing them, showed what sort of boys they are."

And finally the day came when those who were to take part in the raid across the Rhine were to proceed to a point within the French lines from which the start was to be made.

Other Italian planes would await them there, and there they would receive final instructions.

They bade farewell to their comrades in Camp Lincoln, and were given final hand-shakes, while more than one, struggling to repress his emotion wished them "_bonne chance_!"

This raid against one of the largest and most important of the German factory and railroad sections had long been contemplated and details elaborately worked out for it. The start was to be made from the nearest point in French-occupied territory, and it was calculated that the big Italian machines could start early in the evening, cross the Rhine, reach their objective by midnight, drop the tons of bombs and be back within the French lines by morning.

Such, at least, was the hope. Whether it would be realized was a matter of anxious conjecture.

At last all was in readiness. The final examinations of the machines and their motors had been made and the supplies and bombs were in place.

"Attention!" called the commander. "Are you ready?"

"Ready!" came from Tom, who was in command of one machine.

"Ready!" answered Haught, who was in charge of the second.

"Then go, and may good fortune go with you!"

There was a roar of the motors, and the big, ponderous machines started for Germany.

Would they ever reach it?

CHAPTER XXIV

PRISONERS

Under the evening stars, the two big Italian machines slowly, and, it must be said, somewhat ponderously, as compared with a speedy Nieuport, winged their way toward the German river, behind which it was hoped, some day, to drive the savage Huns.

"What do you think?" asked Jack of his chum, for in these latest machines, by reason of the motors being farther from the pa.s.sengers, and by means of tubes, some talk could be carried on.

"I don't know just what to think," was the answer. "So much has happened of late, that it's almost beyond my thinking capacity."

"That's right. And yet I can guess one thing you have in mind, Tom, old scout."

"What is it?"

"Your father! You're hoping you can rescue him."

"That's right, I am. And as soon as this drive is over--if we come back from it with any measure of success, and I can get a long leave of absence--I'm going to make a thorough search for him."

"And I'll be with you; don't forget that!"

There was not time for too much talk of a personal nature, as Tom and Jack had to give their attention to the great plane. The motors were working to perfection, and with luck they should, within a few hours, be over the great German works, which they hoped to blow up.