"We must make our break now," Prescott whispered.

"Lead the way," answered Reade. Fortunately, at this moment, the sentries were at the outer ends of their posts. Bending low, keeping his gaze on the sentries, d.i.c.k scurried noiselessly over the ground until he paused, erect and panting, under the shadow of the building near the rear.

So far safe, for Reade was with him an instant later. While the rear sentry finished his post at this end just beyond the hangar, the front sentry, as far as had been observed, came only as far as the sliding doors of the hangar.

"Get your automatic ready!" d.i.c.k whispered. Then they heard the rear sentry coming toward them.

There came that tense instant when the sentry's pa.s.sing form loomed up within three feet of Captain Prescott. Losing not an instant d.i.c.k sprang upon him with the bound of a panther.

There was no outcry, for d.i.c.k's fingers sought and found the fellow's throat, encircling it. Wrenching the enemy soldier off his balance, Prescott laid him low, the man's bayoneted rifle falling across his body.

It was d.i.c.k's eyes that said, "Ready, Tom!" Reade hesitated for a second or so, then struck the prostrate, choking enemy between the eyes. It was a fearful blow, and the man collapsed.

"One down, but we must get the other!" d.i.c.k whispered sternly.

They stole forward along the side of the building, d.i.c.k in the lead. Peeping around the corner he saw the sentry almost finishing the nearer end of his post. Back came Prescott's head like a shot. He waited until he knew by the tread that the sentry had turned and was going back over his post. Then it was that d.i.c.k stole upon him from behind. Another leap, a grip around the man's throat, and sentry number two was on his back, where Reade gave him the grace blow.

Without a word the chums picked up this sentry, carrying him around to the rear. Then d.i.c.k sought the small rear door of the hangar.

It opened softly, and they entered, closing it behind them.

All was darkness in here until Reade, producing his pocket electric torch, threw a beam of light over the scene.

While d.i.c.k stood still, now holding the automatic pistol, Tom took a rapid look over each of the two air machines.

"This nearer one looks like the newer, better one," Reade declared.

"I'll look over the machinery to make sure that the engine is all right and that I understand the engine and the controls.

Her machine-gun is ready for business and we may need it."

d.i.c.k stood patiently by, wondering how soon the guard was due to be relieved. If that happened soon, and the knocked-out sentries were discovered, the chance for escape looked like three less than nothing!

"All right," whispered Tom at last. "I can handle her, and there is water enough in the radiator and the gas tanks are filled.

Now, then, we must open the doors as noiselessly as possible."

d.i.c.k taking the left-hand one, Tom the right, they rolled the doors back. These moved almost noiselessly.

"Here's the way you turn the engine on," Tom whispered, holding the torch and getting d.i.c.k up into the c.o.c.kpit of the craft.

"Turn it on as soon as I say, but not a second before."

Placing himself in front of the propeller Tom gave it a few brisk turns.

"Now!" cried Tom, leaping back. The ignition caught at once.

Tom clambered over into the c.o.c.kpit, Prescott now being in the observer's seat forward.

With the wheel in his hands and his feet resting against the controls Tom Reade suddenly dropped all apprehension. He was as much at home now as Prescott was with an automatic pistol in his hand.

Waiting only until the engine had gained its speed without missing, Tom cried:

"Ready, pal!"

Out through the open doorway Reade sent the airplane "taxying"

or running along the ground.

Across the field toward them came racing a German aviator with a startled look on his face. He had to jump out of the way as the "taxying" airplane bore down on him. But he reached for his automatic and brought it forth.

"Stop!" he roared. "Turn out the guard!" Bang! bang!

Two bullets whizzed by Tom's head. Prescott fired three shots instantly, one of them taking effect, for the German officer went to earth and lay there, his pistol now silent.

From behind the hangar several members of the guard came rushing from their tents. By the time they were in front of the hangar they could shoot only by guess, and might hit their own comrades in the troop camp. So they fired into the air, wildly, rapidly.

So much shooting was bound to rouse the troop camp, and did.

The sentries came out on the jump. While some fired star sh.e.l.ls that lighted the sky, others took quick aim with their rifles.

Aiming at the figures on the ground as best he could, just as Reade left the ground for the air, Prescott fired, loaded and fired, jamming in a fresh magazine whenever the automatic became emptied.

Twenty feet up in the air, fifty, a hundred! Tom Reade rose as fast as he could make the machine move. More star sh.e.l.ls, and now the anti-aircraft guns came into action.

At three hundred feet above the ground sh.e.l.ls exploded about the fugitives. One lucky shot of the enemy would be enough to bring them to earth.

The pistol was now too hot to use further. d.i.c.k sat back, closing his eyes, while Reade drove at all the speed he could compel, ever rising higher. Both Americans knew that other anti-aircraft guns further south would be turned upon them.

Finally Tom, after a glance at the barograph, roared at Prescott:

"Five thousand feet up on a dark night, and we're going to fifteen thousand feet. All we now have to fear will be other German aircraft, but there'll be fleets of them sent out to look for us!" Prescott nodded, though he could not hear in the roar of the motors and the rush of the air past him.

A mile below them the blackness of the night was punctured by a lively little volcano of red and yellow jets. A dozen anti-aircraft guns opened fire on the fugitive airplane, whose course must have been telephoned along the line. Some of the sh.e.l.ls burst so close that fragments of metal whizzed about the ears of both Americans; some of the sh.e.l.ls went far wide of the mark, but at least two of the gunners followed the moving craft for the distance of a mile with an accuracy that caused the two fugitives in the sky the liveliest uneasiness. The gunners were aiming by the sound of the engines.

"Give us fifteen minutes more at this speed,"

Tom roared, "and we'll be back over our own French lines!"

They were soon going at terrific speed, fifteen thousand feet up in the air, when a terrifying peril beset them.

Out of the blackness ahead, bearing straight at them, came a dozen German airplanes in splendid formation!

CHAPTER XXIV

CONCLUSION

"Hurrah!" yelled Tom Reade. "Sink or swim---but never say die!

Now we'll give it to 'em, real Yankee Doodle, 'over there' style!"

It sounded like sheer bravado, but Reade was fired with the new genius of the war.

Tom headed straight for the nearest plane, and d.i.c.k turned the machine gun loose. Almost immediately he had the great good luck to cripple that enemy and send the craft fluttering down to earth.