“i think we’ll have to give her another dope, collins,” remarked ronnie pryor, as early one summer’s morning he stood before “the hornet,” which, after a night-flight to the sea and back, was reposing in its “nest.”

“it certainly wouldn’t hurt her, sir, especially if we can get some of that new patent stuff that mr. henderson was telling us about the other day,” the young mechanic replied.

“ah! that’s a secret,” laughed his master. “it’s no doubt the finest dope ever invented, and happily fritz, with all his scientific attainments, is still in the dark regarding it.”

“i’m afraid the enemy will learn the secret before long, sir,” the man remarked. “there are far too many strangers knocking about the aerodromes, and prying into everyone’s business.”

“i know, collins, i know,” remarked ronnie. “they’re very inquisitive regarding my new silencer.”

“yes, that’s quite right, sir. i’m often being pumped about it by strangers.”

“well, i know you never utter a word concerning it.”

“trust me, sir,” laughed the clean-shaven young man. “i always deny any knowledge of it. but the people who make the inquiries seem very shrewd indeed. and the funny thing is that they are never foreigners.”

[22]“yes, i quite realise that. but at all hazards we must keep the secret of the silencer to ourselves,” said pryor. “the silencer enables us to make night-flights in secret without the enemy being any the wiser,” he added.

collins grinned. he knew, only too well, how “the hornet” had, more than once, been over to belgium and returned in safety without its presence being spotted by the enemy. he knew, too, that the bomb-rack had been full when ronnie and beryl gaselee had ascended, and that it had been empty when they had returned.

on the previous night pryor had been up, accompanied by his mechanic. they had come in at daybreak, snatched three hours’ sleep, and were now out again overhauling the machine.

as they were speaking, beryl gaselee, dainty and fair-haired, in a cool, white cotton dress, suddenly came up behind them exclaiming:

“good-morning, ronnie! iris is waiting breakfast patiently for you.”

“oh, i really forgot, dear!” replied the young airman. “collins and i have been so busy for the last hour.”

together they crossed the lawn arm-in-arm to the pleasant, old-world house.

when ten minutes later the pair sat down to breakfast in the sunlit dining-room, the long windows of which led out upon an ancient terrace embowered with roses, mrs. remington came in, greeting ronald with the protest—

“i wish, when you come in, you’d put your silencer on your boots, ronnie! you woke me up just at four, and toby started to bark.”

[23]“by jove! did i? lots of apologies! i’ll creep about in my socks in future,” declared the culprit, stooping to pat the miniature “pom.”

“did sheppard give you the telephone message?” mrs. remington asked.

“no. what message?”

“why, one that came in the middle of the night?”

at that moment sheppard, the old-fashioned butler who had just entered the room, interrupted, saying in his quiet way:

“i haven’t seen mr. pryor before, madam.” then turning to ronnie, he said: “the telephone rang at about a quarter to one. i answered it. somebody—a man’s voice—was speaking from liverpool. he wanted you, sir. but i said you were out. he told me to give you a message,” and he handed ronnie a slip of paper upon which were pencilled the words:

“please tell mr. ronald pryor that mark marx has returned. he will be in london at the old place at ten o’clock to-night.”

as ronald pryor’s eyes fell upon that message all the light died from his face.

beryl noticed it, and asked her lover whether he had received bad news. he started. then, recovering himself instantly, he held his breath for a second, and replied:

“not at all, dear. it is only from a friend—a man whom i believed had been killed, but who is well and back again in england.”

“there must be many such cases,” the fair-haired girl remarked. “i heard of one the other[24] day when a man reported dead a year ago, and for whom his widow was mourning, suddenly walked into his own drawing-room.”

“i hope his return was not unwelcome?” said ronnie with a laugh. “it would have been a trifle awkward, for example, if the widow had re-married in the meantime.”

“yes, rather a queer situation—at least, for the second husband,” declared iris, who was some five years beryl’s senior, and the mother of two pretty children.

“did the person who spoke to you give any name?” asked pryor of the butler.

“no, sir. he would give no name. he simply said that you would quite understand, sir.”

ronald pryor did understand. mark marx was back again in england! it seemed incredible. but whose was that voice which in the night had warned him from liverpool?

he ate his breakfast wondering. should he tell beryl? should he reveal the whole curious truth to her? no. if he did so, she might become nervous and apprehensive. why shake the nerves of a woman who did such fine work in the air? it would be best for him to keep his own counsel. therefore, before he rose from the table, he had resolved to retain the secret of marx’s return.

after breakfast ronald, having taken from “the hornet” the essential parts of his newly invented silencer, which, by the way, he daily expected would be adopted by the government, carried them back to the house and there locked them in the big safe which he kept in his bedroom.

then, later on, beryl drove him to the station[25] where he took train to london, and travelled down to his aeroplane factory, where, in secret, several big battleplanes of “the hornet” type were being constructed.

it was a large, imposing place with many sheds and workshops, occupying a considerable area. the whole place was surrounded by a high wall, and, beyond, a barbed-wire entanglement, for the secrets of the work in progress were well guarded by trusty, armed watchmen night and day.

pryor was seated in his office chatting with mr. woodhouse, the wide-awake and active manager, about certain business matters, when he suddenly said:

“by the way, it will be best to double all precautions against any information leaking out from here, and on no account to admit any strangers upon any pretext whatever. even if any fresh government viewer comes along he is not to enter until you have verified his identity-pass.”

“very well,” was woodhouse’s reply. “but why are we to be so very particular?”

“well, i have my own reasons. without doubt, our friend the enemy is extremely anxious to obtain the secrets of ‘the hornet,’ and also the silencer. and in these days we must run no risks.”

then, after a stroll through the sheds where a hundred or so men were at work upon the various parts of the new battleplane destined to “strafe” the huns, and clear the air of the fokkers, the easy-going but intrepid airman made his way back to pall mall, where he ate an early dinner alone in the big upstairs dining-room at the royal automobile club.

by half-past seven he had smoked the post-prandial cigarette, swallowed a tiny glass of[26] grand marnier cordon rouge, and was strolling back along pall mall towards charing cross.

at the corner of the haymarket he hailed a passing taxi, and drove out to hammersmith to a small, dingy house situated in a side-turning off the busy king street. there he dismissed the conveyance, and entered the house with a latch-key.

“cranch!” he shouted when in the small, close-smelling hall, having closed the door behind him. “cranch! are you at home?”

“hullo! is that you, mr. pryor?” came a cheery answer, when from the back room on the ground-floor emerged a burly, close-shaven man in his shirt-sleeves, for it was a hot, breathless night.

“yes. i’m quite a stranger, am i not?” laughed pryor, following his host back into the cheaply furnished sitting-room.

“look here, cranch, i’m going out on a funny expedition to-night,” he said. “i want you to fit me up with the proper togs for the walworth road. you know the best rig-out. and i want you to come with me.”

“certainly, mr. pryor,” was his host’s reply. john cranch had done his twenty-five years in the criminal investigation department at scotland yard as sergeant and inspector, and now amplified his pension by doing private inquiry work. he was “on the list” at the yard, and to persons who went to the police headquarters to seek unofficial assistance his name was frequently given as a very reliable officer.

the pair sat for some time in earnest consultation, after which both ascended to a bedroom above, where, in the cupboard, hung many suits of clothes, from the rags of a tramp—with broken[27] boots to match—to the smart evening clothes of the prosperous middle-aged roué who might be seen at supper at the savoy, or haunting the nightclubs of london. among them were the uniforms of a postman, a railway-porter, with caps belonging to the various companies, a fireman, a private soldier, a lieutenant, a gas-inspector, a tram-conductor, and other guises which ex-detective john cranch had, from time to time, assumed.

within half-an-hour the pair again descended, and entering the sitting-room they presented quite a different appearance.

ronnie pryor’s most intimate friend would certainly not easily have recognised him. even beryl gaselee would have passed him by in the street without a second glance, for his features were altered; he wore a small moustache, and his clothes were those of an east-end jew. at the same time cranch was dressed as a hard-working costermonger of the true old kent road type.

together they drove in a taxi across south london to the railway-arch at walworth road station, beneath which they alighted and, turning to the right along the camberwell road, crossed it and went leisurely into the albany road—that long, straight thoroughfare of dingy old-fashioned houses which were pleasant residences in the “forties” when camberwell was still a rural village—the road which ran direct from camberwell gate to the old kent road.

darkness had already fallen as the pair strolled leisurely along until they passed a small house on the left, close to the corner of villa street.

as they went by, their eyes took in every detail. not a large house, but rather superior to its neighbours, it lay back behind a small garden and[28] seemed closely shuttered and obscure. nearly opposite it cranch’s sharp eyes espied a “to let” board upon a house, and he at once suggested that if they hid behind the railing they could watch the house of mystery in security.

this they did, and after a little man?uvring—for there were many people passing in the vicinity—they both crouched beneath a soot-laden lilac-bush, which commanded full view of all who went from and came to the dark house before them.

as ronnie crouched there in concealment one thought alone kept running through his brain. truth to tell, he was much mystified as to the identity of that mysterious person who, from liverpool, had given him warning.

was it a trap? he had certainly not overlooked such a contingency.

for over an hour and a half the two men remained there, eagerly watching the diminishing stream of foot-passengers until at last, coming up from the camberwell road, ronnie noticed a man approaching.

for some seconds he kept his eye steadily upon him, for the moon was now shining fitfully through the clouds.

“by jove! how curious!” he whispered to his companion. “why, that’s knowles, one of the mechanics at hendon! i wonder what he’s doing over here?”

ronnie was, of course, in ignorance—as was also everyone at the hendon aerodrome—that henry knowles, the hard-working, painstaking mechanic, whose expert work it was to test machines, was not really an englishman as he pretended to be, even though he could imitate the cockney tongue, but that his actual baptismal[29] name was hermann klitz, and his place of birth coblenz, on the rhine.

with wondering eyes the airman watched the mechanic pass into the dark, silent house.

“very strange!” he remarked beneath his breath. “very strange indeed!”

but his curiosity was increased by the arrival, ten minutes later, of a rather short, middle-aged man of distinctly burly build. the newcomer hesitated for a few minutes, gazing about him furtively, as though he feared being followed, and then slipped through the gate up to the house, where the door fell open, he being apparently expected.

“did you see that man, cranch?” asked pryor in a whisper. “that’s germany’s great spy—mark marx. he’s been in america for the past ten months or so, and is now back here upon some secret mission concerning our aircraft—upon which he’s an expert.”

“they’re holding a council here—by the look of it,” remarked the detective. “five of them have gone in—and why, look! here comes another—a lame man!”

“yes,” said ronnie. “this secret place of meeting is known to the spies of germany as ‘number three.’ from here certain of the clever activities of the invisible hand of germany are frequently directed, as from other centres; mark marx is a clever adventurer who used to be the assistant director of the enemy’s operations in this country. apparently he has returned to london to resume his sinister activities against us. he acts directly under the control of the head of germany’s secret service in this country, that shrewd, clever, and influential person who hides his identity beneath the official description of ‘number seven.’”

[30]“then ‘number three’ is the headquarters of ‘number seven’—eh!” asked the ex-detective in a whisper.

“exactly. that some devilish conspiracy is now afoot is quite certain. our duty is to discover and to thwart it. i was secretly warned that mark marx had returned, and now, knowing that it is so, i must take adequate precautions.”

“how shall you act?”

“i have not yet decided.”

“but can’t we endeavour to ascertain what is in progress here to-night, mr. pryor?” suggested cranch.

pryor and his companion kept vigilant watch till far into the night when, about two o’clock in the morning, a big closed motor-car suddenly came along the road, pulling up a little distance from the house. the driver, a tall, thin man, alighted and waited for some moments, when the two men, marx and klitz, alias knowles, emerged carrying between them a small but heavy leather travelling trunk and, assisted by the driver, placed this on top of the car. then the two men entered and drove rapidly away.

“that car may come again to-morrow night,” remarked pryor. “we must lay our plans to follow it.”

next night, pryor having ascertained the identity of the friend who had warned him of mark marx’s return to england, he and cranch were again at the same spot beneath the stunted lilac-bush. round the corner, in villa street, at a little distance away stood ronnie’s closed car with beryl gaselee in charge, the latter wearing the cap and dust-coat of a war-time chauffeuse.

hour after hour they waited until dawn broke.[31] but as no one came to that house known as “number three,” they were compelled at last to relinquish their vigilance.

for four nights in succession they kept the same watch, cranch having revealed his identity and explained to the constable on duty that the car was awaiting an expected friend.

on the fifth occasion, just about half-past one in the morning, sure enough the big, dark-green car drove up, and from it marx alighted and entered the enemy’s headquarters.

presently klitz and another man arrived on foot, and they also entered. subsequently another small but heavy trunk was taken out and placed in the car.

by this time ronnie and his companion had reached their own car, and while cranch and beryl entered, ronnie jumped up to the wheel and started off. he first took a street that he knew ran parallel with the albany road in the direction the car had taken before and, after going a little distance, he turned back into the thoroughfare just in time to see a rear-lamp pass rapidly. quickly he increased his speed, and soon satisfied himself that it was the car he intended following.

they turned at last into the old kent road, and then on as far as a dark little place which ronnie knew as kingsdown. then, branching to the right, keeping the red rear-light ever in view, they went by the byways as far as meopham and on past jenkin’s court, through some woods until suddenly the car turned into a gateway and went across some open pastures.

ronnie saw that he had not been noticed by the driver, who was too intent upon his speed and quite unsuspicious. therefore he pulled up[32] dead, waited for ten minutes or so, and then flew past the gateway at top speed. for nearly a mile he went, and at last came to a standstill upon a long, steep slope with a copse on each side, quite dark on account of the overhanging trees.

having run the car to the side of the road they alighted. ronnie switched off the lamps, and they walked noiselessly back on the grass by the roadside and at length, having turned in at the gateway, saw, in the dim light, a long, low-built farmhouse with haystacks beside it and big barns.

the throb of the car’s engine showed that the germans were probably only depositing the trunk, and did not intend to remain.

the watchers, therefore, withdrew again into the shadow of a narrow little wood close to the house and there waited in patience. their expectations were realised a quarter of an hour later when the two men emerged from the modern-built farmhouse and drove away, evidently on their return to london.

by their man?uvre pryor became greatly puzzled. he could not see why that trunk had been transferred to that lonely farm in the night hours.

after the car had disappeared they waited in motionless silence for some time until, after a whispered consultation, they ventured forth again.

cranch’s suggestion was to examine the place, but unfortunately a collie was roaming about, and as soon as they came forth from their place of concealment the dog gave his alarm note.

“ben!” cried a gruff, male voice in rebuke, while at the same time a light showed in the upper window of the farm.

[33]meanwhile the trio of watchers remained hidden in the shadow of a wall close to the spacious farmyard until the dog had gone back.

ronnie had resolved to leave the investigation until the following day, therefore all three crept back to the car and, after carefully noting the exact spot and the silhouette of the trees, they at last started off and presently finding a high road, ran down into wrotham, and on into the long town of tonbridge.

at the hotel their advent at such an early hour was looked upon askance, but a well-concocted story of a night journey and unfortunate tyre trouble allayed any suspicions, and by seven o’clock the three were seated at an ample breakfast with home-cured ham and farmyard eggs. afterwards, for several hours, beryl rested while the airman and the detective wandered about the little kentish town discussing their plans.

when, at eleven o’clock, ronnie met beryl again downstairs, the trio went into one of the sitting-rooms where they held secret council.

“now,” exclaimed ronnie, “my plan is this. i’ll run back alone to the farm and stroll around the place to reconnoitre and ascertain who lives there. without a doubt they are agents of germany, whoever they are, because it is a dep?t for those mysterious trunks from ‘number three.’”

“i wonder what they contain, dear?” beryl said, her face full of keenest interest.

“we shall ascertain, never fear. but we must remain patient, and work in strictest secrecy.”

“well, mr. pryor, you can play the police game as well as any of us,” declared cranch, with a light laugh.

[34]therefore, a quarter of an hour later, pryor took the car and returning to a spot near the farm—which he afterwards found was called chandler’s farm—and running the car into a meadow, left it while he went forward to reconnoitre.

as he approached, he noticed two men working in a field close by, therefore he had to exercise great care not to be detected. by a circuitous route he at last approached the place, finding it, in daylight, to be a very modern up-to-date establishment—evidently the dairy farm of some estate, for the outbuildings and barns were all new, and of red brick, with corrugated iron roofs.

the farmhouse itself was a big, pleasant place situated on a hill, surrounded by a large, well-kept flower-garden, and commanding a wide view across kent towards the thames estuary and the coast.

and as ronnie crept along the belt of trees, his shrewd gaze taking in everything, there passed from the house across the farmyard a tall man in mechanic’s blue overalls. he walked a trifle lame, and by his gait pryor felt certain that he was one of the men who had been present at that mysterious house called “number three” a few nights before.

but why should he wear mechanic’s overalls, unless he attended to some agricultural machinery at work on the farm?

only half-satisfied with the result of his observations, ronnie returned at length to his companions, when it was resolved to set watch both at albany road and at chandler’s farm. with that object pryor later that day telegraphed to collins calling him to london from harbury, and after meeting him introduced him to the ex-detective.

[35]then that night the two men went to albany road, while ronnie and beryl returned in the car back into kent, where soon after ten o’clock they were hiding on the edge of the little wood whence there was afforded a good view of the approach to the lonely farm.

time passed very slowly; they dared not speak above a whisper. the night was dull and overcast, with threatening rain, but all was silent save for the howling of a dog at intervals and the striking of a distant church clock.

far across the valley in the darkness of the sky behind the hill could be seen the flicker of an anti-aircraft searchlight somewhere in the far distance, in readiness for any aerial raid on the part of the huns.

“i can’t think what can be in progress here, beryl,” ronnie was whispering. “what, i wonder, do those trunks contain?”

“that’s what we must discover, dear,” was the girl’s soft reply as, in the darkness, his strong hand closed over hers and he drew her fondly to his breast.

a dim light still showed in one of the lower windows of the farmhouse, though it was now long past midnight.

was the arrival of someone expected? it certainly seemed so, because just at two o’clock the door opened and the form of the lame man became silhouetted against the light. for a moment he came forth and peered into the darkness. then he re-entered and ten minutes later the light, extinguished below, reappeared at one of the bedroom windows, showing that the inmate had retired.

for six nights the same ceaseless vigil was kept, but without anything abnormal transpiring. the[36] man marx had not again visited the mysterious house in albany road, yet the fact that the obscured light showed nightly in the window of chandler’s farm, made it apparent that some midnight visitor was expected. for that reason alone ronnie did not relinquish his vigilance.

one night he was creeping with beryl towards the spot where they spent so many silent hours, and had taken a shorter cut across the corner of a big grass-field when, of a sudden, his well-beloved stumbled and almost fell. afterwards, on groping about, he discovered an insulated electric wire lying along the ground.

“that’s curious,” he whispered. “is this a telephone, i wonder?”

fearing to switch on his torch, he felt by the touch that it was a twin wire twisted very much like a telephone-lead.

at the same moment, as they stood together in the corner of the field, beryl sniffed, exclaiming:

“what a very strong smell of petrol!”

her lover held his nose in the air, and declared that he, too, could detect it, the two discoveries puzzling them considerably. indeed, in the succeeding hours as they watched together in silence, both tried to account for the existence of that secret twisted wire. whence did it come, and whither did it lead?

“i’ll investigate it as soon as it gets light,” ronnie declared.

just before two o’clock the silence was broken by the distant hum of an aeroplane. both detected it at the same instant.

“hullo! one of our boys doing a night stunt?” remarked ronnie, straining his eyes into the darkness, but failing to see the oncoming[37] machine. away across the hills a long, white beam began to search the sky and, having found the machine and revealed the rings upon it, at once shut off again.

meanwhile, as it approached, the door of chandler’s farm was opened by the tall, lame man, who stood outside until the machine, by its noise, was almost over them. then to the amazement of the watchers, four points of light suddenly appeared at the corners of the grass-field on their left.

“by jove! why, he’s coming down!” cried ronnie astounded. “there was petrol placed at each corner yonder, and it’s simultaneously been ignited by means of the electric wire to show him his landing-place! it’s an enemy machine got up to look like one of ours! this is a discovery!”

“so it is!” gasped beryl, standing at her lover’s side, listening to the aeroplane, unseen in the darkness, as it hovered around the farm and slowly descended.

the man at the farm had brought out a blue lamp and was showing it upward.

“look!” exclaimed pryor. “he’s telling him the direction of the wind—a pretty cute arrangement, and no mistake!”

lower and lower came the mysterious aeroplane until it skimmed the tops of the trees in the wood in which they stood, then, making a tour of the field, it at last came lightly to earth within the square marked by the little cups of burning petrol.

the pilot stopped his engine, the four lights burnt dim and went out one after the other, and the lame man, hurrying down, gave a low whistle which was immediately answered.

then, on their way back to the farm, the pair[38] passed close to where the watchers were hidden, and in the silence the latter could distinctly hear them speaking—eagerly and excitedly in german!

beryl and ronnie watched there until dawn, when they saw the two men wheel the monoplane, disguised as british with rings upon it, into the long shed at the bottom of the meadow, the door of which the lame man afterwards securely locked.

an hour later pryor was speaking on the telephone with cranch in london, telling him what they had discovered. soon after midday beryl and ronnie were back at harbury, where in the library window they stood in consultation.

“look here, beryl,” the keen-faced young man said, “as that machine has crossed from belgium, it is undoubtedly going back again. if so, it will take something with it—something which no doubt the enemy wants to send out of the country by secret means.”

“with that i quite agree, dear.”

“good. then there’s no time to be lost,” her lover said, poring over a map. “we’ll fly over to chandler’s farm this afternoon, come down near fawkham, and put the ’bus away till to-night. then we’ll see what happens.”

“he’ll probably fly back to-night,” the girl suggested.

“that’s exactly what i expect. i’ve told collins and cranch to meet us there.”

an hour later the great battleplane, “the hornet,” ronnie at the joy-stick, with beryl in air-woman’s clothes and goggles strapped in the observer’s seat, rose with a roar from the big meadow at harbury and, ascending to an altitude of about ten thousand feet, struck away due south across the patchwork of brown fields and[39] green meadows, with their tiny clusters of houses and white puffs of smoke all blowing in the same direction—the usual panorama of rural england, with its straight lines of rails and winding roads, as seen from the air.

the roar of the powerful twin engines was such that they found conversation impossible, but beryl, practised pilot that she was, soon recognised the town over which they were flying.

soon afterwards the thames, half-hidden in mist and winding like a ribbon, came into view far below them. this served as guide, for ronnie kept over the river for some time, at the end of which both recognised three church spires and knew that the most distant one was that of fawkham, where presently they came down in a field about half-way between the station and the village, creating considerable sensation among the cottagers in the neighbourhood.

collins, who was awaiting them near the station, soon arrived on foot to render them assistance, the ’bus being eventually put beneath a convenient shed used for the shacking of hay.

ronnie had not used the silencer, fearing to create undue excitement among the anti-aircraft boys, many of whom had, of course, watched the machine’s flight at various points, examining it through glasses and being reassured by its painted rings.

until night fell the lovers remained at fawkham, taking their evening meal in a small inn there, and wondering what cranch had seen during the daylight vigil he had kept since noon. collins had left them in order to go on ahead.

as dusk deepened into night both pryor and his well-beloved grew more excited. the discovery they had made was certainly an amazing[40] one, but the intentions of the enemy were still enveloped in mystery.

that something desperate was to be attempted was, however, quite plain.

in eagerness they remained until night had fallen completely, then, leaving the inn, they returned to the farmer’s shed, and, wheeling forth the powerful machine, got in and, having bidden the astonished farmer good-night, ronnie put on the silencer, started the engines, and next moment, rising almost noiselessly, made a wide circle in the air. taking his bearings with some difficulty, he headed for a small, open common, which they both knew well, situated about a quarter of a mile from chandler’s farm.

there, with hardly any noise, they made a safe descent. scarcely had the pilot switched off the engines, when the faithful collins appeared with the news that marx and the man knowles had arrived from london in the car at seven o’clock.

presently, when collins had been left in charge of the ’bus, and ronnie and beryl had stolen up to where cranch was waiting, the latter whispered that marx and knowles had both accompanied the german pilot down to the shed wherein the disguised machine was reposing. “they’re all three down there now,” added the ex-detective.

“did they bring anything in the car?”

“yes. half-a-dozen cans of petrol. they’ve just taken them down to the shed.”

and even as he replied they could hear the voices of the three returning. they were conversing merrily in german.

another long, watchful hour went by, and the darkness increased.

“if he’s going over to belgium it will take[41] him about an hour and three-quarters to reach zeebrugge—for that’s where he probably came from,” remarked the expert pryor. “it’s light now at four, so he’ll go up before two, or not at all.”

“he would hardly risk being caught at sea in daylight,” declared beryl.

then, for a long time, there was silence, the eyes of all three being fixed upon the door of the farm until, of a sudden, it opened and the lame man and the enemy pilot were seen to emerge carrying between them one of the old leather trunks that had been brought from london.

“hullo! they’re going to take it across by air!” cried pryor. “it must contain something which ought to remain in this country!”

they watched the trunk being carried in silence away into the darkness to the shed. then presently the two men returned and brought out the second trunk, which they carried to the same spot as the first.

“h’m!” remarked ronnie, beneath his breath. “a devilish clever game—no doubt!”

then, instructing cranch to remain and watch, he led beryl back to where “the hornet” stood.

into the observer’s seat he strapped the girl, and, hopping in himself, whispered to collins to get all ready.

the engine was started; but it made no sound greater than a silent motor-car when standing.

ronnie and beryl strained their ears to listen for the sound of the engine of the enemy ’plane.

those moments were full of breathless tension and excitement. “the hornet” was waiting to rise.

suddenly there was a loud sound of uneven motor explosions in the direction of the farm.[42] the engine was firing badly. in a few moments, however, it was rectified, and the loud and increasing hum told ronnie that the enemy had risen.

“stand clear,” he shouted to collins, and then, as he pulled over the lever, “the hornet” dashed forward and was soon rising rapidly, but in silence.

so dark was it that he could not distinguish the enemy. yet, heading for the coast, as he knew that was the direction the german had taken, he rose higher and higher until five minutes later beryl, at his orders, suddenly switched on the searchlight and swept around below them.

at first they could distinguish nothing, yet from the direction of the humming they knew it must be below them.

two minutes later ronnie’s quick eyes saw it in front of them, but a hundred feet or so nearer the ground.

the enemy pilot, alarmed by the unexpected searchlight in the air, suddenly rose, but ronnie was too quick for him and rose also, at the same time rapidly overhauling him.

beryl, holding her breath, kept the searchlight with difficulty upon him as gradually “the hornet” drew over directly above him.

quick as lightning ronnie touched a button.

there was a loud swish of air, followed a second later by a dull, heavy explosion in the valley far below.

the bomb had missed!

the enemy was still rising, and from him came the quick rattle of a machine-gun, followed by a shower of bullets from below.

ronnie pryor set his teeth hard, and as he again touched the button, exclaimed:

“take that, then!”

next second a bright flash lit up the rural[43] landscape, followed by a terrific explosion, the concussion of which caused “the hornet” to stagger, reel, and side-slip, while the enemy aeroplane was seen falling to earth a huge mass of blood-red flame.

on the following day the evening papers reported the finding of a mysterious wrecked and burnt-out aeroplane “somewhere in kent.”

the pilot had been burnt out of all recognition, but among the wreckage there had been discovered, it was said, some metal fittings believed to be the principal parts of some unknown machine-gun.

only ronald pryor and beryl gaselee knew the actual truth, namely, that the enemy’s secret agents, at marx’s incentive, had stolen, the essential parts of a newly-invented machine-gun, and that these were being conveyed by air to within the german lines, when the clever plot was fortunately frustrated by “the hornet.”