fighter.

Now and then the young airman managed to glimpse Tom's well known machine, for the two chums had decorated their planes with distinguishing marks that they could recognize even when a great distance away. The other was fighting with two of the foe, and was having a serious time of it, spinning like a reel, darting downward to avoid being raked by machine-gun fire, and then coming up on the tail of a Hun with the advantage all on his side.

Jack, still denied his share of action, continued to watch Tom out of the corner of his eye. He felt like giving a shout when presently he saw one of the Hun machines plunge downward as though a shot had paralyzed the arm of the pilot. Over and over it went, bursting into smoke and flames while speeding toward the earth.

There could be no doubt but that Tom would add another count to his score, though he was already reckoned an ace, being accredited with seven clear-cut victories.

But the other Hun aviator had taken advantage of the thrilling moment to dart in and deliver a hot fire. Jack could see the spurt of the machine-gun as it blazed away furiously, the two planes passing one another. He felt his heart in his throat for fear that Tom might be caught napping, for the distance was too great to make sure of what was happening.

Suddenly a cold hand seemingly clutched Jack's heart. Tom was falling rapidly! It was no nose-dive, but bore all the marks of either an engine gone dead or of some mishap to the pilot. So did gallant Tom's plane vanish from the sight of his horrified chum, being swallowed up in the dense volumes of smoke rolling upward from the battleground below. Jack's heart felt like lead in his breast.

CHAPTER II

YANKEE PLUCK

When Tom Raymond sent one of his Hun opponents whirling down toward the far distant earth he naturally experienced the glow that comes to a victor in a stubbornly contested battle.

The gratification was all the more profound because of the fact that he had taken on two adversaries at the same time. Any air pilot who was capable of holding his own against an enemy numerically superior had reason to feel satisfied.

He quickly saw, however, that this did not mean the end of the fight. That other crafty Hun had swung unexpectedly and was now pouring in a furious fire. Tom realized that his assistant had ceased firing. Had the machine-gun become jammed? He was hanging partly from his seat. Was he badly injured in the bargain? Still, despite all this handicap, Tom would possibly have come through in good shape had not something happened to his engine just then. After all, even a Liberty motor could play a trick on its pilot master, just as that fine French engine on his former Spad machine had done a few times.

The airplane started to shoot downward at frightful speed, leaving the Hun far behind. Tom kept his head, and bent every energy to trying to get the motor started again, meanwhile working also to keep on a fairly level keel. He had passed through a similar experience on other occasions, but never when hovering over the German lines with a battle in progress under him.

A sickening sensation gripped his heart, for it flashed before his mind that this might be the end. Like every other aviator, he had defied Fate every time he went up, and at last the dreadful moment had come for him to pay the price!

Not for a single second, even while feeling that queer sensation grip him, did Tom cease working frantically to start his engine. He knew he had one last forlorn chance left. A few seconds would tell the story, and either he must be lucky enough to have his balky engine suddenly start again in response to his frantic efforts, or else—well, he dared not allow himself to dwell on what would happen to him when he struck the ground with all the frightful momentum of his falling machine.

The air service boy lived ages in that brief period of time. Never could he forget the agony that gripped his soul. There flashed before his memory the faces of those he loved at home, those whom he might never see again.

Then it was over. The engine had suddenly yielded to his frantic efforts, and once more commenced to throb with renewed life. Tom, with tremendous exertion, managed to right his tottering plane and steady it on an even keel.

His observer lay in a huddled heap in his seat. But for the safety belt he must have slid into space. Tom could not tell whether he was dead or had simply swooned.

That was a matter for the future. Just now he must concern himself with the task of extricating himself from his fresh perilous position. So rapidly had he fallen that amidst the swirling smoke clouds he could plainly see the Germans just below; and that he must be visible to his enemies he quickly had reason to understand.

Even as he started to spin away, shrapnel burst close beside his plane. Machine-guns also began to chatter underneath, and he saw that the wings of his plane were being cut by the hail of missiles that came up in swarms, like buzzing bees, each armed with a sting.

Dodging this way and that in eccentric lines, Tom brought into play all his acquired knowledge of a pilot's tricks in order to avoid being made a victim of this hot fire. He fully expected that, after all, the enemy would get him, but he was grimly determined that it would be only after he had exhausted every device possible.

He kept his head, and while dodging back and forth managed to follow a general course that promised soon to carry him closer to the American front. At one time he found himself above what seemed to be a very inferno of destruction. The air palpitated with the shock of a terrible explosion, as though a great mine had been fired. But Tom knew what it meant.

That must be the Big Bertha which for some days now had played an important part in shelling the rear of the American lines, even to knocking a temporary field hospital into fragments.

How Tom wished just then that his had been a bombing plane. With what savage joy would he have dropped his whole supply of air torpedoes down upon that mighty engine of destruction, forever silencing its thunderous voice and ending its power to do injury to the cause in which his whole soul was enlisted!

After that his way became somewhat easier, for Tom had succeeded in climbing higher, so that he was screened from the gunners below. Then he found himself passing over the American front, with the open field in sight where the temporary aerodromes could be seen, looking like dingy patches of yellow earth.

Of course there was nothing to do but to return immediately. His observer was injured, if not dead, and would need looking after; while Tom felt that his machine could hardly be called in trim for further work, as it needed a thorough overhauling after the recent rough treatment accorded to it by the fighting Boches.

Despite his crippled machine, the young air service boy managed to make a fairly good landing, with the help of several orderlies and attendants. They had come on the run, understanding that something was wrong, because the observer hung part-way over the side, and it could be seen that the plane itself had been in action.

Tom's first thought was of his comrade. He himself had received only one small cut in the arm from flying shrapnel splinters, though it persisted in bleeding profusely, and would have to be tied up at the nearest field dressing-station.

He breathed easier when he discovered that his observer, while badly injured, would have more than a fighting chance to pull through. A doctor was quickly on the spot, and