# Air Service Boys over the Rhine/Chapter 17

CHAPTER XVII
SEEKING THE GUN
Tom and Jack gazed blankly at one another. The same thought was in the minds of both.
"The spy!"
"That's who did it," declared Tom. "He forged our names to a note—no hard task since neither Bessie nor her mother knows our writing very well—and he's induced them to go some place where he could get them in his power again."
"But why?" asked Jack.
"Probably because Potzfeldt wanted him to do it. He still has his eye on Mrs. Gleason's property, I presume, if there is any left after his robbery."
"It certainly is tough to think that Bessie and her mother have again fallen into his clutches!" exclaimed Jack. "And we can't do a thing to rescue them. We've got to report with the others in the morning at the new aerodrome."
"Yes, but we still have to-night free!" cried Tom. "It will give us several hours to make a search, and we'll do it! Do you know where ​Mrs. Gleason and Bessie went in response to this forged note?" he asked the landlady.
She mentioned a certain restaurant, not far away, where Tom and his chum had frequently eaten with Mrs. Gleason and her daughter.
"She was rather surprised to get the note from you," said the landlady, "and wondered why you didn't come yourself. But she supposed it had something to do either with your search for your father or with war matters, so she did not question the messenger. I heard her mention the place where she and Bessie were going, or I would not know."
"How long ago was it?" asked Jack.
"Oh, just before luncheon time. And they haven't come back."
"The scoundrels have a long start of us!" exclaimed Jack. "We'll have to do the best we can."
"Better notify the police at once," suggested Tom. "We'll need their help."
"That's right," agreed his chum.
Their uniform was an open sesame to the police officials, and a detective was at once detailed to go with the boys to the restaurant. There, as might have been expected, there was no news. The spy, or whoever Potzfeldt's agent was, had been too clever for that. All that could be learned from a taxicab driver was that a lady ​and a girl, answering the descriptions of Bessie and her mother, had been met in front of the restaurant by a man.
The three, after a short talk, had driven off together in an automobile, and that was the last seen of them.
"But we'll get some trace," declared the detective. "It is hard to get in or out of Paris now without proper papers. And while, of course, this spy may have forged documents, there is a chance that we may intercept him and help your friends. Time is against us, but we will do our best."
Tom and Jack knew that. There was nothing else to do, and so, worried as they were, they went back to their comrades. Tom made some inquiries about his father, but, as he feared, no news had come.
As may be imagined Tom and Jack did not pass a very restful night. The Zeppelin raid had set their nerves on edge, as well as those of every one else, and it could not be told when the big gun might begin firing again. Then the fact of Mrs. Gleason and Bessie being missing, and not knowing in what danger they might be, added to the boys' anxiety.
They paid a late visit to the police, hoping for news, but the spy had not been apprehended. Then they hurried back to get a little rest ​before starting with their comrades of the air to search for the monster gun.
While these events were transpiring, the French army intelligence department had not been idle. The officials knew how vitally necessary it was, in order not to have the morale of the people of Paris weakened, to do something to find and silence the big guns. And first it was ncessary to discover them.
While this, as yet, had not been done with exactness, owing to the concealing tactics of the Germans, it was believed that the long-range cannon was hidden in a certain wood near Laon. French airmen had endeavored to spy out certain positions there, but an unusually large number of German planes had fought them off.
"That's pretty good evidence that there must be something doing," observed Tom, when he heard this information. "Laon is about ten miles behind the German lines as they exist at present. Just a breather for a good French plane. Jack, that's a trip we'll soon be taking."
"I'll be with you, old scout. How's your hand?"
"Oh, all right now. I can hold the joy stick or work the gun. I'm ready for whatever comes along."
The time had come for the picked squadron ​to leave Paris and assemble at the aerodrome assigned to them as their headquarters while the search for the big gun was in progress. Sad at having to leave without having some word of Mr. Raymond, and without knowing the fate of Bessie and her mother, Tom and Jack, nevertheless, bore up well and left with their comrades, going out of Paris on a train that would eventually bring them to their head-quarters.
In a way their mission was a secret one. Yet it was a question if the Germans did not guess that something like what really was afoot would be undertaken in order to silence the super-cannon. They were up to all the tricks of war, and they must have realized that the French would do as the Germans themselves would do under similar circumstances.
"Well, this sure is some place!" exclaimed Tom, as they reached the camp where they were to stay until the gun had been destroyed, or until some other change in plans was necessary. "It's the best aerodrome we've struck since we began flying in this war."
"I believe you!" echoed Jack.
The place, though newly established just back of the French lines, where they opposed the German trenches, was well fitted up for the purpose to which it was to be devoted.
​There were a number of canvas hangars for the aeroplanes, there were living quarters for the men, a wireless station and a well defended camp where the aviators might live in comfort during the periods between their flights.
Of course the place was open to attack by German fliers, but this was true of every place along the line. Sufficient camouflaging had been done, however, to render the spot reasonably secure from bombing. Of course a direct attack from in front would be met by the admirable French system of defense, and there were plenty of reserves that could be brought up if a general advance were attempted by the Germans. But as there was no particular place of any military or strategic importance on that sector, the worst that was to be feared was an attack from the air.
And this would be guarded against both by the French fliers themselves and by a battery of the newest type of anti-aircraft gun.
"They don't seem to have forgotten much," observed Tom, as he and Jack, with the others, went to the quarters assigned to them.
"You said something!" exclaimed Jack, admiringly.
Thus had been set up in this locality, where heretofore no aircraft activities had been carried on to any extent, a most perfect escadrille.
​It was designed to destroy the big German cannon. Would it succeed?
That was a question every man of the Allies asked.
Shortly after the arrival of the picked squadron at the camp, which, in honor of Tom and Jack had been named "Lincoln," word came in over the wireless that the big gun had again fired on Paris.
"It's funny we didn't hear any report of it," said Jack.
"There have been reports enough," Tom remarked. "I've heard the booming of distant guns ever since we got near this place. Any one of them may have been the monster, or they may have been firing other guns to hide the sound of this cannon. Then, too, it may not make as much noise as we think it ought to. The Germans may have found a new kind of powder, or even some propelling gas, that makes no extraordinary report. In that case we couldn't locate the gun by the sound."
"Maybe you're right," agreed Jack. "Anyhow they're firing, that much is proved; and it's somewhere over there," and he motioned toward the German lines.
Much as the airmen desired to start at once in their search for the monster cannon, it was deemed wise to have first a consultation and a ​general understanding of what means should be employed.
Then, too, all the aircraft were new, having been shipped to Camp Lincoln and there assembled, and it was desired to test them before taking the dangerous flights over the German lines. So the airmen would have to spend some time—perhaps half a week—in preliminary work.
Meanwhile the great cannon would keep up its deadly, though, from a military standpoint, useless work.
And so began the preparation, if such it might be called. Every one, from the most daring "ace" to the humblest kitchen helper in the camp, was anxious for the day when it could be said that the gun was out of commission, or guns, if, as was likely, there was more than one. But the men in command knew the value of thoroughness. There must be no failure through lack of making proper plans.
But at last everything was in readiness. The planes had been tested, keyed up, and the motors run until every part of them was humming like a top. Each man felt confidence, not only in himself but in his craft, and that meant much. There were several types for the fliers to use, single-seaters, the big bombing craft, those equipped for slow flying and from which ​photographs were to be taken, as well as others. The taking of photographs was expected to help in revealing the position of the hidden gun.
The big Italian plane was not ready, it seemed, to be used, but it would be soon, it was said.
Then came the day and the hour when certain members of the picked squadron were to take the air to look for the gun. Tom and Jack, to their delight, were selected to go.
"What a chance!" exclaimed Jack, as he climbed into his machine, and saw that he had plenty of ammunition for the Lewis gun.
"I hope we can make good!" returned Tom.
Then they were away and up, seeking to find the monster cannon that was bringing the war into the heart of Paris.