The sound of digging! The blows of a mattock!

  A cold perspiration broke out on Jack's forehead as he realized theimport of this. They were digging his grave, and by a refinement ofcruelty, within earshot of his prison place. Whether by accident ordesign, poor Jack was being forced to hearken to the most grisly of thepreparations for the next morning's reveille.

  So the hours crept by leaden-footed. Sleep was out of the question asmuch as was possibility of escape. The sound of the digging, which Jackhad stopped his ears to keep out, had ceased.

  Then came a sudden stir outside. The sound of hurrying feet and commandsbarked in sharp, quick voices. Jack's heart gave a bound.

  Could it be a detachment of Belgians summoned by Tom and Bill coming towipe out the small force occupying the farm?

  He flung himself against the door of the smoke house, listeningintently. There was a tiny crack at one of the posts and through this hecould command a limited view of the moonlit farmyard. Then came an oddsound. Like the dry whirring of insects in the fall. It grew in volume.The hurrying and the shouts increased, too. Shots were heard, scatteringone after the other and a yell that sounded like a shout of warning.

  Then the world rocked and spurted flame. Screams and groans filled theair.

  Again there came an explosion that shattered the night and sickened thesenses. Jack, half stunned, fell to the floor of the smoke house as partof its roof was torn off.

  Then came silence, broken an instant afterward by groans and moans andswift, alarmed orders. There was a rat-a-plan of hoofs. The queerwhirring sound died out. Only the moans still continued. Dizzy and sick,Jack got to his feet.

  As yet he could not quite realize what had happened. Suddenly followedrealization.

  A night raiding aircraft had spied the shifting lights of the encampmentand, by the moonlight, caught the gleam of stacked arms, and had struck.

  The sound of the sentries' ceaseless pacing had stopped. Jack shoutedand pounded on the door of the partially wrecked smoke house, but therewas no answer but the moans and cries that were now getting fainter andless frequent. The sides of the smoke house were of rough logs andwithout much difficulty Jack clambered to the shattered roof.

  He raised himself and clambering over, gave a hasty glance about him. Itwas a terrible scene of wreckage that he surveyed. In the earth twoimmense holes, big enough to bury two horses, had been torn, and closeby lay two men. Over toward the house was a third figure stretched out.Three horses, one of which died as Jack was looking over the carnage,lay not far off.

  There was nobody else in sight.

  Jack clambered over the edge of the gap the shell had torn in the roofand dropped lightly to the ground.

  "Wasser!" moaned one of the wounded men, whom Jack recognized as one ofhis guards. The boy sped to the well and hastened back with the bigearthen pitcher from which they had refreshed themselves earlier thatday.

  But he was too late. Even as the boy held the cooling draught to thesentry's lips, the man died. The other was already dead when the boydropped to the ground, his body frightfully shattered by the aerialbomb.

  There was still the third man lying by the house and Jack, thinking hemight be able to minister to him, hurried over. But here, too, the bombhad struck fatally.

  A shaft of moonlight fell through the poplars and illumined the man'sface. It was Radwig, struck down in death even as he had planned a cruelrevenge for another. Jack covered the dead professor's face with theman's huge blue cloak and then stood silent for a moment. The rapiditywith which it had all happened almost stunned him.

  Fifteen minutes before he had been a prisoner with the hideous sounds ofspade and mattock in his ears. Now he was, by nothing short of amiracle, free again. He raised his face to the sky and his lips movedsilently. Then, with a last look about the place, he prepared to leave,fervently hoping that before another day had passed he would be with hisfriends once more in Louvain.

  All at once he heard a loud whinny. One of the dead troopers' horses hadbeen left behind in the mad flight from the farmhouse. It was saddledand bridled, although the girth had been loosened. Jack untied it,tightened the girths, and mounted. He did not know much about riding,but somehow he managed to stick to the animal's back as he directed itdown the road.

  Every now and then he drew rein and listened. He had no desire toencounter prowling bands of Uhlans or to run into the small force thathad evacuated the farmhouse, no doubt believing him to be dead. But dawnbroke while he was still traveling, not at all certain that he was goingin the right direction.

  Jack decided to abandon his mount. Taking off its bridle so that itcould find forage along the roadside, he patted its neck and said:

  "Thanks for the ride, old fellow."

  Then bareheaded, and tired almost to exhaustion by all he had gonethrough, yet driven on by dire necessity of reaching the Belgian lines,the lad struck off across a wheat field into a path of woodland. On theedge of the field he shrank suddenly back into the tall wheat. There laya man's coat, a stone jug and a basket. No doubt the man was close athand. But although he crouched there for a long time, nobody came, norwas there any sound of human life. Birds twittered and once a rabbitcocked an inquisitive eye at the lad as he lay crouched in the wheat.

  Cautiously Jack raised himself and parting the stalks, peered out. Hesaw something he had not noticed before. The man, who doubtless ownedthe belongings which had alarmed Jack, lay stretched out at the foot ofa tree. He was on his face sleeping.

  But was he sleeping?

  An ugly, dark stain discolored the ground around him. His shirt was dyedcrimson. Jack saw, with a shudder, that he had nothing to fear here. Thepoor peasant was dead. Shot down by wandering Uhlans no doubt, as he wasabout to gather his harvest.

  "Poor fellow, he'll never need these now," said Jack, as driven bythirst and hunger he investigated the stone jug and the basket. One heldcider, the other the man's dinner of black bread, onions and coarsebacon.

  Too famished to mind the idea of eating the dead man's dinner, Jackstuffed his pockets, took a long pull of the cider jug and then plungedinto the wood. Here he flung himself down to rest and eat. Then, tiredas he was, he forced himself to rise and travel on again.

  Faint and far off the distant rumble of cannonading came to his ears,but here in the woods it was as calm and peaceful as if war, death andslaughter were forgotten things. At length he came to a place where thewoods thinned out and there was a small clearing. He was about toadvance across this when he saw something that caused his heart to givea quick leap and stopped him short in his tracks.

  At one side of the clearing was an aeroplane!

  It was a big monoplane with gauzy, yellow wings and a body painted thecolor of the sky on a gray day, no doubt to make it invisible at anyconsiderable height.

  Any doubt that it was a war machine was removed by the sight of a smallbut wicked-looking rapid-fire gun that was mounted on its forward part.

  Jack was still looking at it, rooted to the spot as if he had been afigure of stone, when there was a sudden crackle on the floor of thewood behind him.

  Then came an order sharp and crisp.

  "Arrette!"

  Jack was not a French scholar but there was something in the way thecommand was given that made him stand without moving a muscle. Footstepscame behind him and then he felt rather than saw a man passing from therear to face him.

  He worked round to the front of the boy and then Jack saw that he was asmall man with carefully waxed mustache in whose hand was a particularlyserviceable-looking revolver, which he held unpleasantly level at Jack'shead.

  CHAPTER XXXIII.

  THROUGH BULLET-RACKED AIR.

  The man with the revolver gave a sudden cry:

  "_Mon ami_ Read-ee!"

  "Great Scott, de Garros!" gasped Jack, recognizing the French aviator."What are you doing here?"

  "I might ask zee same question of you," smiled the other. "I leave
youon zee sheep and now, voila! I find you in a Belgian wood wizout zeehat, wiz your face scratched by zee bramble and looking--pardon me,please,--like zee tramp."

  "I guess I do," laughed Jack, in his relief at finding that instead offalling again into the enemy's hands, he had met an old friend; "but I'mlucky that there's nobody to say 'how natural he looks'----"

  "Pardon, I don't understand," said de Garros in a puzzled tone.

  Jack plunged into a recital of his adventures, interrupted frequently bya hail of "_Sacres_," "_Nom d'un noms_," and "_Chiens_," from theFrenchman.

  "And now it's up to you to explain how I find you here in the heart of aBelgian wood with a war machine," said Jack as he concluded.

  "Zat is eezee to explain," said the Frenchman. "After you leave me inNew York I get passage on a French liner for Havre. We arrive and I amat once placed in command of zee air forces of Belgium. Since zat time,pardon my conceit, monsieur, I think zat wizout bragging I can say I'ave cause zee Germans very much trouble. Last night I fly over zeecountry and where I see Germans I drop a little souvenir,--but what iszee matter, monsieur, you look excited."

  "No, no, go on," said Jack; "I was just thinking that it's possible theday of miracles has come back."

  De Garros stared at him but went on:

  "In zee course of my journey I see a farmhouse where Gerrman cavalryhorses and stacked arms show in zee moonlight," said the Frenchman.

  "How did you know they were Germans?" asked Jack.

  "Did you not know all zis territory is now overrun by zem? Yesterdaythey advance. They are now near Louvain. But nevaire fear, someway wedrive zem back. But to continue. I drop one, two bomb wiz my complimentsand----"

  "Saved my life!" exploded Jack.

  De Garros looked concerned.

  "Once more pardon, my dear Readee, but you are well in zee head? Zeesun----?"

  "No, no, don't you see?" cried Jack; "those were your bombs thatresulted in my being saved from a spy's death."

  "_Sacre!_ Ees zat possible? And yet it must 'ave been so! Embrace me, mydear Readee, nuzzing I 'ave done 'ave give me so much plaisair as zees."

  Jack had to submit to being hugged by the enthusiastic little aviator towhom, as may be expected, he felt the deepest gratitude.

  "And now what are zee plan?" asked de Garros, when his enthusiasm hadsubsided.

  "I want to join my friends in Louvain," said Jack.

  "_Nom d'un chien!_ You are trying to walk zere through zees part of zeecountry!"

  "Why, yes. I----"

  "_Mon ami_, you might as well commit zee suicide. It is swarm wizGerman. I hide in zees wood till night when I can travel wizout havingzee bullet swarm like zee bee round what you call zee bonnet."

  "Then what am I going to do?" he demanded. "I can't stay here and I'vehad one experience with the Germans, and I assure you it was quitesufficient to last me for a lifetime."

  "I 'ave zee plan," said de Garros.

  "Yes."

  "My aeroplane hold three people."

  "Go on."

  "You shall fly wiz me."

  "To Louvain?"

  "If that is possible. If not, to some place where you can communicatewiz your friend. 'Ow you like zat?"

  Jack hesitated a moment. He was not a timid lad, nor did he fearordinary danger. Yet flying above the German troops, between the placewhere they were talking and Louvain, was a risky business to say theleast of it.

  Yet there was no alternative that he could perceive. The mere idea ofgetting captured by Uhlans again gave him goose flesh. As if he read histhoughts de Garros said:

  "You run no more of zee reesk in zee flight than you do on zee ground.Not so much. At night I fly high and I promise you I will not make anyattacks."

  "You're on," said Jack, extending his hand.

  CHAPTER XXXIV.

  A FLIGHT OF TERROR.

  "Take zees. You need zem. We fly fast. _Tres vite._"

  De Garros was speaking as he handed Jack a pair of goggles. It was duskand they, having finished an excellent meal from the aviator's provisionpannier, were about to start on their flight across the war-smittencountry.

  Already the flying man, aided to the best of Jack's ability, had goneover the aircraft, testing every part of it. Everything was in perfectorder, from the big Gnome eight-cylindered, self-contained motor,mounted with the big propeller forward, to the last bolt on thedragonfly tail.

  Just before full darkness fell, which might have involved them in anaccident in rising, de Garros gave the word to get on board. Theyclambered aboard, Jack with a heart that beat and nerves that throbbedrather more than was comfortable.

  There are few people who do not feel a trifle "queer" before their firstflight above the earth, and in Jack's case the conditions of danger weremultiplied a hundred-fold, for before they had cleared the woods andrisen to a safe height they might be the target for German rifles andquick firers. De Garros wore a metal helmet padded inside. Jack had tobe content with an old cap that happened to be in the aeroplane, leftthere by some machinist.

  But, as de Garros said, the metal helmet would not be much protectionagainst the projectile of a quick firer, or even a rifle.

  The fighting aircraft was fitted with a self-starter, obviating thenecessity of swinging the great propeller.

  "All ready?" asked the Frenchman of Jack, who sat behind him, tandemwise, in the long, narrow body of the machine.

  "Ready," said Jack, in the steadiest voice just then at his command.

  "Then up ve go."

  The self-starter purred, and then came the roar and a crackle of theexhausts as the propeller swung swiftly till it was a blur. Blue smokefrom the castor-oil lubricant spouted, mingled with flame, into thethickening air of the evening. The wholesome smell of the wood wasdrowned in the reek of gasoline and oil fumes.

  "Gracious, if there are any Germans within a mile, they'll hear thisracket," thought Jack, with a gulp. "It sounds like a battery of gatlingguns."

  De Garros took his foot from the brake lever and the machine dartedforward. Jack clutched the sides desperately till his knuckles showedwhite through the skin. Then he gave a shout of alarm.

  The machine had suddenly reared up like a startled horse. The joltingand bumping of the "take-off" stopped. The boy realized with a thrillthat they were flying.

  At that instant from the trees on one side of the clearing burst severalUhlans.

  "Germans!" cried Jack.

  "Maledictions!" exclaimed the Frenchman.

  For a second or two the Uhlans stood paralyzed as the machine shotupward. They had heard the staccato rattle of the engine from where theylay camped, not far off in the same woods that had sheltered de Garrosand Jack. Thinking it betokened a skirmish, they had hastily run towardthe noise just in time to see the wasp-like machine whirr its wayskyward.

  But the machine was not well above the trees when they recovered fromtheir surprise. Rifles were leveled.

  "Look out!" cried Jack, "they are going to fire on us."

  "Hold tight now, I show you zee trick," rejoined the flying man quietly.

  The aeroplane was now above the wood which on that side was a mere beltof tall trees. Suddenly the machine ceased its upward flight. Itrocketed downward like a stone. Above it bullets whistled harmlessly asthe Uhlans fired at the place where it had been and was not.

  The ground rushed up to meet them as the machine plummeted downward.Jack's head swam dizzily.

  "We'll be killed sure!" he thought, but strangely enough, without muchemotion, except a dull feeling that the end was at hand. Then just asdisaster seemed inevitable, the machine suddenly began to soar again asJack could have sworn it grazed the tall grass.

  Up and up they shot, in a long series of circles, and then de Garrosturned and grinned at Jack, showing his white teeth.

  "'Ow you like?" he asked.

  "I--I guess. I'll tell you after a while" rejoined Jack, with suspendedjudgment.

  T
he earth lay far below them now, although it was still light enough tosee the fields marked off like the squares on a chess board and thecountless fires of the Germans that dotted the landscape almost as faras could be seen. At every one of them were men, who, if any accidentbefell the machine and it had to descend, would make things veryinteresting for the air travelers.

  Jack could not help thinking of this as the aeroplane flew steadilyalong, her motor buzzing with an even sound that told all was goingwell. But he knew they were not out of danger yet.

  A hundred things might befall before they arrived safely in Louvain.

  CHAPTER XXXV.

  THE BULLY OF THE CLOUDS.

  And then all at once the danger came.

  Ahead of them loomed, in the darkness, for the moon had not yet risen, abulking dark form.

  An exclamation burst from the Frenchman's lips.

  "A Zeppelin. Malediction!"

  "Do you think she'll attack us?" asked Jack.

  "I don't know. I can't tell yet which way she is coming. Ah!"

  A long ray of light, like a radiant scimitar, glowed suddenly from themighty aircraft, 400 feet long and capable of carrying many men and tonsof explosives.

  Hither and thither the ray was flung.

  "Zey heard our engines. Zey look for us!" exclaimed de Garros.

  He shot up to a greater height. He was manoeuvering to get above theZeppelin, where her guns would be useless against the aeroplane, whichwas more mobile and swifter in the air than the Kaiser's immensesky-ship.