"What's the move?" enquired Kenneth Kenyon.

"Ask me another, old son," replied his chum, Peter Bramsdean. "Fosterdyke is a cautious old stick, but he knows what's what. There's something in the wind, you mark my words."

"Then you're going to see him?"

"Rather! And you too, old bean. Where's a pencil? We can't keep the telegraph boy waiting."

Bramsdean tore a form from a pad, scribbled on it the reply--"Fosterdyke, Air Grange, near Blandford. Yes, will expect motor to-morrow morning," and he had taken the initial step of a journey that man had never before attempted.

Kenyon and Bramsdean were both ex-flying officers of the Royal Air Force. What they did in the Great War now matters little. Sufficient is it to say that had they belonged to any belligerent nation save their own they would have been styled "aces"; but since in the Royal Air Force details of personal achievements were deprecated, and the credit given to the Force as a whole, they merely "carried on" until ordered to "get out," or, in other words, be demobilised. Then, each with a highly-prized decoration and a gratuity of precisely the same amount as that given to an officer who had never served anywhere save at the Hotel Cecil, they found themselves literally on their feet, relegated to the limbo of civilian life. It was not long before they found how quickly their gratuities diminished. Like many other ex-members of His Majesty's Forces, they began to realise that in smashing the German menace they had helped to raise a menace at home--the greed and cupidity of the Profiteer.

They were just two of thousands of skilled airmen for whom as such there was now no need. Commercial aviation had yet to be developed; trick flying and exhibition flights lead to nothing definite, and only a very small percentage of war-time airmen could be retained in the reconstituted Air Force.

Kenyon and Bramsdean were not men to "take it lying down." They had pluck and resource and a determination to "get a move on," and within a twelvemonth of their demobilisation they found themselves partners and sole proprietors of a fairly prosperous road transport concern operating over the greater part of the South of England.

But it wasn't the same thing as flying. Looking back over those strenuous years of active service, they remembered vividly the good times they had had, while the "sticky" times were mellowed until they could afford to laugh at those occasions when they "had the wind up badly."

Then, with a suddenness akin to the arrival of a "whizz-bang," came a telegram from Sir Reginald Fosterdyke, asking the chums to see him on the morrow.

Sir Reginald Fosterdyke had been Bramsdean's and Kenyon's O.C., or, to employ service phraseology, a Wing-Commander. On his demobilisation he went to live at Air Grange, a large old-world house standing on high ground, a good five miles from Blandford. Very rarely he left his country-house; his visits to town were few and far between, and his friends wondered at the reticence of the versatile and breezy Fosterdyke. He seldom wrote to anyone. When he did, his correspondence was brief and to the point. More frequently he telegraphed--and then he meant business. In pre-war days Air Grange was famous for its week-end house parties. The shooting, one of the best in the county of Dorset, was an additional source of attraction to Fosterdyke's guests. But the war, and afterwards, had changed all that. Few, very few, guests were to be found at Air Grange; the staff of servants was greatly reduced, the well-kept grounds developed a state of neglect. Sir Reginald's friends came to the conclusion that the baronet had become "mouldy." They wondered what possessed him to live an almost hermit-like existence. Fosterdyke knew their curiosity, but he merely shrugged his shoulders and "carried on." His work in the world of aviation was by no means ended. It might be said that it was yet a long way from attaining its zenith.

Early on the morning following the receipt of the baronet's telegram Sir Reginald's car pulled up in front of the premises used as the headquarters of the Southern Roads Transport Company. Kenyon and Bramsdean, having given final instructions to their work's foreman--a former flight-sergeant R.A.F.--jumped into the car, and were soon whisking northwards at a speed that was considerably in excess of that fixed by the regulations.

Although of a retiring disposition, Sir Reginald Fosterdyke had made a point of keeping in touch with his former officers. He had a sort of personal interest in every one of them, and on their part they regarded him as one of the best. Whenever, on rare occasions, Fosterdyke ran down to Bournemouth he invariably looked up Bramsdean and Kenyon to talk over old times. But being invited to Air Grange was quite a different matter. Vaguely, the chums wondered what it might mean, conjecturing ideas that somehow failed to be convincing. Yet they knew that there was "something in the wind." They knew Sir Reginald and his methods.

Through Blandford, up and past the now deserted hutments where formerly German prisoners led an almost idyllic existence in their enemy's country, the car sped on until it gained the lofty downs in the direction of Shaftesbury. Then, turning up a steep and narrow lane, the car drew up at the gate of Air Grange.

It had to. There was no gate-keeper to unlock and throw open the massive iron gates. That task the chauffeur had to perform, stopping the car again in order to make secure the outer portals of Sir Reginald's demesne.

While the car remained stationary the two occupants looked in vain for a glimpse of the house. All they could see was a winding, weed-grown road, with a thick belt of pine trees on either hand. To the left of the road and under the lee of the trees were half a dozen wooden huts, unmistakably of a type known as temporary military quarters. Smoke issuing from the chimneys suggested the idea that they were in "occupation," and a couple of dungaree-clad men carrying a length of copper pipe on their shoulders confirmed the fact. Somewhere from behind the trees came the sharp rattle of a pneumatic drilling machine.

Kenyon glanced at his companion.

"What's the Old Man up to, I wonder?" he enquired. "Quite a labour colony. Look--air flasks too, by Jove!"

A pile of rusty wrought-iron cylinders stacked on the grass by the side of the path recalled visions of by-gone days.

"Something doing, that's evident," agreed Bramsdean. "What's the stunt, and why are we hiked into it?"

"Wait and see, old bird," replied Kenyon.

The chauffeur regained the car and slipped in the clutch. For full another quarter of a mile the car climbed steadily, negotiating awkward corners in the rutty, winding path, until, emerging from the wood, it pulled up outside the house of Fosterdyke.

No powdered footman awaited them. On the steps, clad in worn but serviceable tweeds, stood Sir Reginald Fosterdyke himself.

The baronet--generally referred to by his former officers as the Old Man--was of medium height, broad-shouldered, and deep-chested. He was about thirty-five years of age, with well-bronzed features, clean shaven, and possessed a thick crop of closely-cut dark brown hair tinged with iron grey.

He held out his left hand as Kenyon and Bramsdean ascended the stone steps--his right hand was enveloped in surgical bandages--and greeted his guests warmly.

"Glad to see you, boys!" he exclaimed. "It's good of you to come. Have a glass of sherry?"

He led the way to the study, rang a bell, and gave instructions to a man-servant whom Kenyon recognised as the O.C.'s batman somewhere in France.

Sir Reginald sat on the edge of the table and whimsically regarded his former subordinates. At that moment, rising above the staccato rattle of the pneumatic hammer, came the unmistakable whirr of an aerial propeller. To Kenyon and Bramsdean it was much the same as a trumpet-call to an old war-horse.

"Sounds like old times, eh?" remarked Sir Reginald.

"Rather, sir," agreed Kenyon heartily, and, at a loss to express himself further, he relapsed into silence.

"Experimental work, sir?" enquired Bramsdean.

Fosterdyke nodded.

"Yes," he replied in level tones. "Experimental work, that's it. That's why I sent for you. I'm contemplating a flight round the world. Keen on having a shot at it?"