Jack never saw the sun set with less regret than he did on that occasion. Still he knew that long hours must pa.s.s before the moon would peep in view above the eastern horizon.

As he sat, he allowed his thoughts to roam backward. Once more in imagination he could see his friends who were on the other side of the ocean. Then for a change he would take another "snack," as he called it, for lack of anything else to occupy his attention.

Several times also he dozed, but always arousing with a start at some sound, under the impression that it might be Tom who had come, and, not finding him, gone away again.

Finally he began to believe it must surely be past midnight; and the late moon would presently be making an appearance. On looking closely toward the east he became aware that the heavens were betraying such a fact, for a distinct silvery glow was beginning to appear, low down.

Then came a streak of light. It was the moon. Slowly she mounted higher, as if more or less ashamed of the dilapidated appearance of her usually smiling face.

Jack had earlier in the night changed his place of lodging. He again occupied his former quarters close to the spot where he and Tom had landed when they wished to overhaul the motor that was acting so badly.

The minutes dragged.

Then once more Jack bent his head, and put a hand up to his ear to listen. He laughed to himself with glee.

"That's Tom coming!" he muttered joyously. "I knew Tom wouldn't fail me.

All the same I'll be mighty glad when I'm aboard the plane and on the air route to Bar-le-Duc and my own cot."

Louder grew the sounds. There could not be the slightest doubt about it now, Jack decided. A plane was coming at top speed, and keeping not a great distance above the treetops of the little valley in which the house of Carl Potzfeldt and the road to Metz lay.

Louder grew the insistent drumming. Jack wondered whether some of those at the chateau might not also hear the racket, and, guessing what it would mean, hasten out to the field in time to give Tom and himself a volley of shots.

Now the plane was coming, like a great condor of the Andes about to alight on a mountain peak. Jack gauged full well where it would land. He ran with all his might to be close to the spot. The less time wasted in getting him aboard the better for their safety, he believed, remembering what cause Carl Potzfeldt now had for being suspicious when a plane visited his meadow.

Then the big Caudron ran along the ground and came to a full stop.

"Jack!"

"Yes, Tom, I'm here, and mighty glad to see you!" cried the lad who had counted the minutes until his brain seemed to reel with the strain.

"Get aboard in a hurry, Jack. We've no time to waste here."

"I know that even better than you do," returned the other.

There was indeed need of haste. The air service boys could hear voices from where the chateau was located. Someone had heard the humming of the oncoming airplane. It was Potzfeldt himself, and now he and two of his men came hurrying out on the field, all armed with pistols.

Jack only waited to give the propellers a whirl, and then, as the motor took up its work, he made a leap for his seat. Oh, how good it seemed to be once more in that airplane!

"Stop! Stop!" roared a guttural voice in German. "Stop, or we fire!"

Now the airplane was moving along the ground, b.u.mping and rocking considerably. But Tom knew how to manage, and presently the plane commenced to soar slowly upward.

Loud and angry voices announced the fact that Carl Potzfeldt had arrived close enough to get a view of the rising plane in the misty light of the moon.

"Stop! I command you! Stop!" roared the German. And then came the crack!

crack! crack! of firearms.

The air service boys, because of the noise of the motor, did not hear the discharge of the pistols, but suddenly Jack heard the spatter of a bullet as it struck the machine close beside him. Then he ducked and made a motion to Tom to let his chum know that they were under fire.

But the machine was gaining headway rapidly, and presently they were so high that those below could no longer reach them. Up and up they went until they were thousands of feet above the valley that had been the scene of this remarkable adventure.

Tom headed back along the course he had just come. It was now easy to pick up one landmark after another, and in due course of time they pa.s.sed over the lines once more. Of course, the sound of the plane's propellers was heard by the Germans, and some shrapnel was sent after them; but as Tom was careful to keep high in the air, this did not reach them, and soon they were out of the danger belt.

Fifteen minutes later they made a landing, this time on the well remembered aviation field of Bar-le-Duc. Here there were attendants on hand ready to care for the machines.

"Glad to see you got back," said one of the attendants, grinning. He knew that Tom had gone off on the second trip to bring Jack.

The two air service boys found a car to take them to the villa. The long ride through the night air had made both of them very sleepy, and yet neither felt just then like retiring.

"It's a lucky thing, Tom," said Jack, between yawns, "that I had this fur-lined pilot's coat along with me. Only for that I'd have been mighty cold out there in the open last night, with no chance for a fire."

"Well, it's all past now, Jack. Tell me what happened to you during my absence."

Jack, was nothing loath, and as quickly as possible gave his chum the particulars of how he had gone into hiding and almost been betrayed by the dog.

Tom had already told Jack about what had become of Mrs. Gleason and Bessie. They had been taken to a house some miles back of the lines, and were to be made comfortable there for the night.

"And early in the morning they are to start for Paris," Tom said with satisfaction. "I managed through our captain to get them pa.s.sage aboard a train that is to take some wounded back to the base hospitals. Mrs.

Gleason says she means to stay in Paris and help all she can as a Red Cross nurse, for she has had some experience in nursing."

"That's fine!" was Jack's comment. And then for the time being he became somewhat silent.

Tom could easily understand that his chum was cherishing a hope that some time or other when they were taking a vacation from their arduous duties while flying for France, the pair of them might visit the French metropolis, and if so they would certainly try to see Bessie and her mother again.

"And I've got more news to tell," remarked Tom, when the pair were about to turn in for their much-needed sleep. "You'll remember about that message we found in the capsule on the leg of the homing pigeon. Well, one of the other pigeons we found was used to send a false message to the Germans, telling them that a certain part of the French line was very weak. A short while later the Germans made a furious attack on that part of the line, and, believe me, they caught it for fair--the plucky French soldiers, aided by the artillery, literally wiped up the ground with them."

"That's great news!" cried Jack. "Then it paid to bring down that pigeon, didn't it?"

"It sure did, Jack!"

Two days later came a most important announcement, especially to the American airmen.

"Things are coming our way at last," the valiant commander announced, as they crowded about him. "The papers this morning say that Uncle Sam has at last got his back up. Any day may now bring the glorious news from across the Atlantic, telling that the United States has taken the steps that will put her in this World War against the Central Powers. Then it will be all over but the shouting."

"That's right!" cried Jack.

"You just leave it to Uncle Sam to do it!" added Tom.

Many more adventures were in store for the young aviators, and what some of them were will be related in the next volume of this series, to be ent.i.tled "Air Service Boys Over the Rhine; Or, Fighting Above the Clouds."

And here for the present let us leave the air service boys and say good-bye.

THE END

THE d.i.c.k HAMILTON SERIES