CHAPTER XIII.

  CAUGHT IN THE ACT.

  What had happened was no mystery to Rob and Merritt, though possiblyTubby, not quite so apt to jump to conclusions, remained a littlebewildered at what was going on.

  It seemed that the Belgians must have suspected something wrong, andpossibly followed the bearer of the lantern when he went into the openfield to flash his signals toward the sky.

  The three scouts from across the ocean were not the only watchers whohad read that message. Yes, and the coast had not been as clear as thesignal man believed, since even then enemies must have been creepingtoward him, though utterly unseen in the darkness.

  The rapid discharge of guns, and the loud outcries of men engaged indesperate warfare, thrilled the boys. They could not see a singlefigure, but the spiteful flashing of firearms, as they were discharged,told them that the fight was not all one-sided, and that the Germansmust be resisting capture with their usual valor.

  All at once they heard another sound.

  "It's the motor--the aeroplane man has managed to get going!" exclaimedRob, instantly comprehending what that meant.

  In order to rise, after starting his machine, it was necessary for theaviator to first skim along the field for a little distance, andgradually gain an impetus which, at the proper instant, results in aslow ascent.

  Of course he was taking all sorts of desperate chances in making thisblind venture; but his life was at stake, if caught. Besides, heundoubtedly must have examined the nature of that level stretch ofground before, and selected it as a landing place on account of its goodqualities.

  "He's heading this way, Rob!" exclaimed Tubby, almost in a panic.

  "If he butts into this wall it'll spell his finish!" added Merritt.

  "No danger of that," said Rob. "He knows every foot of ground aroundhere. But duck down, everybody. They will fire a volley after him, andwe might get in line of the bullets."

  Tubby dropped flat, forgetting that the high stone wall was as good abreastwork as any one could want.

  Just as Rob had anticipated, there was a series of explosions, and theycould even hear the patter of bullets striking the piled-up stonescomposing the wall.

  This was enough to tell them that the fleeing aviator had headedstraight toward the spot where they were crouching. And, as the rattleof his machine grew louder, they realized that he was approaching themwith considerable speed.

  Then, with an additional clatter, the Taube passed over the wall,clearing its top by not more than ten feet.

  "Keep down!" exclaimed Rob, feeling Merritt beginning to make a move,and afraid lest he should stand upright in order to better follow theprogress of the aeroplane.

  It was well he spoke when he did, for another burst of firing came. Thesoldiers were sending random volleys after the fleeing airman, in hopesof injuring his machinery or wounding the aviator himself.

  "That was sure a great getaway!" bubbled Tubby, still seated there onthe ground.

  "But I rather think they winged him," added Merritt, possibly with anote of regret in his voice.

  It was not that he felt any particular sympathy for the German cause;but, boy-like, he could admire grit and daring, no matter under whatflag it might be found. That bold flight of the Taube operator in theface of the flying missiles was quite enough to arouse the spirit of anyone with red blood in his veins.

  "What makes you say that?" asked Tubby, not meaning to remain inignorance when he possessed a ready tongue.

  "I was pretty sure the machine wabbled as it passed over," said Merritt.

  "My opinion, too," Rob chimed in. "It seemed to me he was trying hisbest to get it to mount, but it balked. That could only mean somethinghad gone wrong with the machinery, or else a wing had been fractured."

  "Huh! you talk just like the machine might be a baseball pitcher,"commented Tubby. "But, if that's the case, the chances are he'll drop tothe ground right away, or else smash up against some tree."

  "Just what may happen to him," agreed Merritt.

  "You'll notice that the sound of motor and propeller has suddenly diedout," suggested Rob, "which I take it looks pretty rough for theman-bird."

  "Oh! that would be too bad, now!" Tubby whimpered, as he imagined hecould see the bold pilot of the crippled flier dashed to the groundamidst the wreckage of his machine.

  "Well, the shooting seems to be over!" remarked Merritt.

  "I wonder what happened to the spy?" Rob observed, as he stared over thetop of the stone wall toward the spot where the late confusion had takenplace.

  They could still see that little glow, proving that the lantern had notbeen kicked over in all the riot when the creeping Belgians had pouncedon the enemy.

  "Would it be wise for us to head over there now, Rob?"

  Plainly Merritt was curious to know what had happened, and his manner ofputting this question to the patrol leader showed that he would never besatisfied unless they made some sort of attempt to solve the mystery.

  This time he found Rob more agreeable. Conditions had changedconsiderably since the leader had put his foot down upon any suggestionthat they thrust themselves into the game. The Belgians were theirfriends, and they could not believe any danger was to be feared fromthat source.

  "We might walk over that way," Rob admitted slowly; "that is, if Tubbycan get over this wall."

  "If not, he could wait for us here," suggested Merritt, with a chuckle.

  "I see myself waiting all alone on the other side of the wall, while youtwo step forward and find out all there is going on. I can climb walls,all right, if somebody only gives me a little boost. Try me, and see,Rob. That's a good fellow!"

  Of course Rob was ready to lend the desired assistance; and as Tubbysecured a hold on a large stone that crowned the wall, he was able tohunch himself up, puffing and grunting at a great rate.

  It was easy enough to get down, if one did not care how he fell; butTubby proved fortunate in finding toe places where he could secure ahold, and in some fashion managed to "dismount."

  He pattered after his two chums, who were already moving toward themiddle of the big field.

  Rob, always noticing things as he went along, found that the field wasvery level, and he could understand how the place must have beenselected for a rendezvous since it offered such exceptional facilitiesfor an aeroplane to land and start up again.

  Perhaps this had been a regular nightly affair, and all sorts ofvaluable information may have been carried to the German Headquartersby means of this novel air route.

  As the three boys gradually drew nearer the place where the lanterncould still be seen, they discovered that it was now being held in thehand of some person who wore a uniform.

  "Belgians, all right!" muttered Rob, after noting that the garb was notlike the khaki-colored clothes of the British troops, nor yet the blueand red of the French soldiers.

  There seemed to be more than a dozen of the men, showing that they hadcome in force. Whether they had discovered the spy by accident orfollowed him to the place of meeting, Rob, of course, could only guess;nor did it matter to him.

  "I can see the prisoner!" whispered Merritt.

  "Yes, and there seem to be two of them," added Rob, noting that the menwere being held by several soldiers, and it was as though the officer incommand might be questioning them closely, for a voice could be heardspeaking in French.

  "They've been up against hard knocks, it looks like," Tubby mentioned,eager to let his chums know he was close at their heels, and able tosee a few things for himself.

  Indeed, the men did have the appearance of having been through the mill.Their hats were missing, so that their hair hung about their faces,which looked as if they had been brought in contact with a pile-driver,for there was blood, also contusions and bruises visible.

  "And one of them stands as if he hadn't any use for his left leg, whichmeans most likely he's got a bullet through it," Rob continued.

  He spoke aloud, and for a reason. It were better t
hat the soldiers inthe field learned of their advance by some such method as this. If, onthe other hand, the trio of scouts were detected advancing in any sortof suspicious manner they might be unfortunate enough to evoke a volley.Excited men sometimes shoot first and ask questions afterward.

  A harsh voice suddenly demanded in French to know who they were, andwhat they had to say for themselves; adding that unless they repliedinstantly the order to cut them down would be given.

  "Advance, and hold up your hands above your heads!" heordered.--_Page 149._]