"He sees us!" said d.i.c.k, as Yvette set the Mohawk on a flat downward slant. Two minutes later they struck the water with a mighty splash just as the motor-launch tore up, flinging a cloud of spray into the air as she rushed to their rescue. They were safe and they had saved a throne! But the gallant Mohawk sank to the bottom of the Adriatic.

There was no revolution in Galdavia. With the d.a.m.ning evidence of the film and the phonograph record the Allies acted promptly, and with the traitor Mestich dead the plot went to pieces. King Milenko rules to-day over a contented, happy and prosperous people, and his early follies laid aside has become a capable and popular ruler. Fedor they never saw again; he was killed in a motor smash a week after they left, and the secret of his wonderful invention died with him.

CHAPTER THREE.

THE SEVEN DOTS.

In a cosy little house at Veneux Nadon, near Moret-sur-Loing, in the great Forest of Fontainebleau, d.i.c.k, Yvette, and Jules were seated in earnest conversation. They made a remarkable trio. d.i.c.k was unmistakably English, Yvette and her brother as unmistakably French--the girl dark-haired and dark-eyed, and with all the grace and vivacity which distinguish Frenchwomen of the better cla.s.s. Her brother, quiet and dreamy, lacked his sister's vivacity, but there was a suggestion of strength and iron resolution in the firm mouth and steely eyes.

"It will be terribly dangerous, d.i.c.k," said Yvette, with an altogether new note of anxiety in her voice.

"I suppose it will," replied d.i.c.k, "but,"--and his voice hardened as he spoke--"I don't see what else we can do. We cannot run the risk of seeing a perfected helicopter in German hands. It would be too fearful a weapon. We must get hold of the plans and destroy the machine, whatever the risk may be."

Strange stories had come through the French Secret Service of a new and wonderful type of aircraft which was being tested with the utmost secrecy somewhere in the neighbourhood of Spandau, the great military town near Berlin. Of its precise character little was known or could be ascertained, and even Regnier, the astute and energetic head of the French Secret Service, had at length to confess himself utterly beaten.

His cleverest agents had been baffled; more than one was in a German prison, with little hope of an early release. In the meantime the mysterious machine flitted about the neighbourhood of the great garrison, always at night, appearing and disappearing under circ.u.mstances which proved conclusively that it must be of a type which differed widely from any yet known to the public.

"We must go, d.i.c.k," said Yvette, "and Regnier is extremely anxious that you should help us. His trouble is that while he has dozens of capable men at his command none of them has a really expert knowledge of aviation. He thinks that if you once got a good look at the machine you could form a complete idea of what it really is."

"Very well," said d.i.c.k, "we will look upon it as settled. We must work out a plan."

For many months d.i.c.k Manton had been working steadily and secretly at Veneux Nadon under the auspices, though not actually in the employ, of the French Secret Service. He had offered the plans of the Mohawk to the British War Office, only to be met with a reception so chilly as effectually to discourage him from proceeding further in the matter.

Regnier, however, was a man of a different stamp from the British bureaucrat--keen as mustard and with the saving touch of imagination which is characteristic of the best type of Frenchman. He had unbounded faith in Yvette, who had for some time been one of his most trusted lieutenants, and when, angry at the att.i.tude of the British War Office, she had given him a hint of what the Mohawk could really do, he had offered d.i.c.k the fullest facilities for continuing his work. Under the circ.u.mstances d.i.c.k had felt that to refuse would have been absurd.

Veneux Nadon was a lonely little spot. Here d.i.c.k, though only thirty miles from Paris, found himself in complete seclusion, with a well-equipped workshop in large grounds completely buried in the lovely forest, and thoroughly screened from prying eyes. Regnier had put the matter to him quite plainly.

"You are an Englishman, Monsieur Manton," he had said, "and I will not ask you to sell your secret to France. But we are willing to bear the expense of perfecting your invention on the distinct understanding that when the time comes England shall have the option of sharing in it to the exclusion of all other countries except France. When you are ready we will officially invite the British Government to send a representative and will give them the opinion of coming in on equal terms. I do not think we can do more or less."

So it was settled, and for many months d.i.c.k and Jules had toiled on the building of a new Mohawk whose performances far surpa.s.sed those of the machine lost in the Adriatic. It was now completed and its preliminary tests had satisfied them that they had forged a weapon of tremendous potency.

The machine was of the helicopter type. The idea, of course, was not new, but d.i.c.k had solved a problem which for many years had baffled inventors whose dream it was to construct a machine which should have the power of rising vertically from the ground and remaining stationary in the air.

Driven upward by powerful propellers placed horizontally underneath the body, the Mohawk was capable of rising from the ground at a tremendous speed. Once in the air the lifting propellers were shut off and the machine moved forward under the impulse of the driving screws placed in the front and rear. These screws were the secret of d.i.c.k Manton's triumph. They were of a new design, giving a tremendous ratio of efficiency. In size they wore relatively tiny, but possessed far greater power than any propeller known. The machine itself was nearly square. The body was completely covered by the big, single plane, measuring about twenty feet each way. This was the outside size of the machine and so perfectly was the helicopter controlled that d.i.c.k had repeatedly brought it to earth in a marked s.p.a.ce not more than thirty-two feet square.

Fitted with the new silencer which d.i.c.k had discovered and applied to the old Mohawk with such signal success, the engine was practically noiseless. At high speed the tiny propellers emitted only a thin, wailing note, barely audible a few yards away. Time and again d.i.c.k had sailed on dark nights only a few feet above the house roofs of Paris and had found that the noise of the ordinary traffic was amply sufficient to prevent his presence being discovered.

To ensure absolute secrecy the various parts of the machine had been made in widely separated districts of France, and had been brought from Paris to Veneux Nadon, where d.i.c.k and Jules had carried out the erection of the machine alone. The very existence of the new aeroplane was utterly unsuspected by the few villagers who lived in the neighbourhood.

Keenly interested in his work d.i.c.k had thoroughly enjoyed the peaceful life in the depths of the beautiful forest. He and Jules had become the closest of friends, and with Yvette, whose winning personality seemed to bind him to her more closely day by day, they made up a happy house party. They were looked after by a capable old peasant woman who was the devoted slave of all three, but whose admiration for Yvette seemed to rise almost to the point of veneration.

On the day following the conversation recorded above, they were surprised to receive a visit from Regnier himself--an alert, dark-eyed man who seemed seriously perturbed.

"There is no time to be lost," he declared. "I hear to-day from Gaston that he has managed to get a near view of the new German machine. He says it rose apparently from the flat roof of a house standing in its own grounds outside Spandau. He happened to be near and caught sight of it just in time. Of course it was dark and he could see no details.

But he is positive that the machine rose nearly straight up from the flat roof at an angle far too steep for any of our machines. That alone is sufficient to show that the Germans have got hold of something new and valuable. He waited for a long time, and finally saw the machine return. He declares it landed again on the roof. Evidently, Monsieur Manton, they have found out something along the lines of your invention, even if they have not actually got your secret."

"How far away was Gaston when he saw it?" asked d.i.c.k.

"It must have been at least a quarter of a mile," replied Regnier, "as the grounds are very extensive. Gaston dared not venture an attempt to get inside; the high fence is utterly unscalable, and the two lodge gates are always kept locked and there is a keeper at each."

"And he heard the engine?"

"Yes, he says so specifically," replied the Chief.

"Well," said d.i.c.k, "at any rate we are ahead of them to that extent. If it had been my machine he would not have heard the engine at all at that distance."

"However," he went on, "it is evidently time we acted. Now, Monsieur Regnier, Mademoiselle Pasquet has told me what you want. I am willing to go. But I shall have to take the Mohawk. How are we to hide it? I can get over and back at night safely enough, but to hide the machine in the day-time will be another matter."

"Gaston can arrange that," the Chief declared. "You know he has a farm a short distance outside, Spandau. There is a big barn there with no sides, and your machine can be easily dragged into it and concealed during the day. You know Gaston is pa.s.sing as a German farmer. He has acted for years for us in this way and has never even been suspected.

But you could not stay long."

"Very good," said d.i.c.k. "I think the best plan will be for Jules to go by motor and for Mademoiselle to go separately by train. They must find out somehow exactly where the German plane is lodged and, if possible, where the plans are likely to be kept, and I must act accordingly. In any case, there will be no difficulty in smashing up the machine, but unless we destroy the plans as well they will be building another too soon to suit us. I will go to Verdun and wait there with the Mohawk until the time comes for me to fly over."

Jules and Yvette left the next day. Jules' car was quite an ordinary one, but it had one important detail added. In the hollow flooring was cunningly concealed a small but powerful wireless telegraph set, the power for which was supplied by the engine. It was highly efficient, but had one serious drawback; it could only be used while the car was at rest owing to the necessity for running an aerial wire up some tall structure, such as a building or a tree. This, in a country where every one was specially suspicious of spies, was a serious peril.

Three days later seven mysterious dots began to excite the ungovernable curiosity of the wireless world!

Jules and Yvette, on arrival in Berlin, had taken rooms adjoining one another at the "Adlon," the big cosmopolitan hotel which is always crowded with visitors from every country under the sun. Yvette posed as a school teacher on an educational tour, but her position was one of great danger. It was impossible to disguise her face, and although she had done what she could to destroy her French individuality by wearing peculiarly hideous German clothes, there was the ever-present danger that she would be seen and recognised by some of the many German agents who during the war had learnt to know her features, and who had good reason to remember her daring exploits in Alsace.

At the same time, in order to have a possible retreat in a humbler neighbourhood, Yvette had hired a room in one of the mean quarters of the town, putting in a few miserable sticks of furniture and giving out that she was a sempstress employed at one of the big shops.

She and Jules had decided never to speak in public. It was essential, however, that they should be able to communicate freely, and through the wall between their rooms Jules had bored with a tiny drill a hole through which he had pa.s.sed a wire of a small pocket telephone. They could thus talk with ease and with the doors of their rooms locked they were absolutely safe from detection so long as they spoke in a whisper.

It was on a dark night, the sky obscured by heavy ma.s.ses of clouds, that d.i.c.k rose in the Mohawk from the Forest of Fontainebleau and headed for Verdun. A couple of hours' flying brought him over the fortress and he descended in a clearing in a dense wood where he was welcomed by Captain Le Couteur, the chief engineer of the military wireless station.

Covered with big tarpaulins, the Mohawk was left under the guard of a dozen Zouaves, and d.i.c.k and Captain Le Couteur motored to the citadel.

Here the Captain took d.i.c.k directly into the steel-walled chamber deep under the fortifications which was the brain of the defences of Verdun.

It was the nucleus of the entire system of telegraph and telephone wires which, in time of war, would keep the commander of the troops in the district fully informed of everything that was happening in every sector of the defences. The innermost room of all, where none but the Captain himself had access, contained the secret codes which dozens of foreign agents would have willingly risked their lives to possess. Their efforts--and they knew it--would have been in vain, for the chamber was guarded day and night by a band of picked men whose fidelity to France was utterly beyond the possibility of suspicion.

"Your messages have already started--the seven dots at intervals of seven seconds," said Captain Le Couteur when they were comfortably seated in the innermost room. "I got half a dozen test calls last night and everything seems to be working well. I expect they are arousing some interest, for operators all over Europe will be mystified. There will be another call about nine o'clock and in the meantime you had better get some sleep. I will call you if anything happens."

d.i.c.k stretched himself on a couch and slept peacefully. Nine o'clock found him with Captain Le Couteur seated in the innermost room at a table covered with delicate wireless apparatus. Turning a switch, the Captain lit up the row of little valves, put the receiving set in operation, and a.s.suming one headpiece himself, handed another to d.i.c.k.

He placed his hand upon one of the ebonite k.n.o.bs of the complicated apparatus and slowly turned it. Then he turned a second condenser very carefully.

"We are on the ordinary six-hundred-metre wave-length now," the Captain explained, "and shall remain so until we get our seven dots. I am bound to keep the machine so or I should miss other messages I ought to hear.

But we will change as soon as we get your signal."

Presently they came, sharp and clear, dot-dot-dot-dot-dot-dot-dot.

Immediately Captain Le Couteur made some swift adjustments.

"Now listen," he said, "we are on a three-hundred-and-fifty-metre wave-length."

A moment later came three M's--three pairs of dashes.

"That's Code Five," said Captain Le Couteur. "Now we shall get the real message."

It came in what to d.i.c.k was a gibberish of letters and figures, but Captain le Couteur wrote it down and then, decoding it, read it off with the skill of the expert. It ran: