"The Star was not far from right, Walter," he added, seriously. "If the battleship plans could be stolen, other things could be—other things were. You remember Burke of the secret service? I'm going up to Lookout Hill on the Connecticut shore of the Sound with him to-night. The rewrite men on the Record didn't have the facts, but they had accurate imaginations. The most vital secret that any navy ever had, that would have enabled us in a couple of years to whip the navies of the world combined against us, has been stolen."

"And that is?" I asked.

"The practical working-out of the newest of sciences, the science of telautomatics."

"Telautomatics?" I repeated.

"Yes. There is something weird, fascinating about the very idea. I sit up here safely in this room, turning switches, pressing buttons, depressing levers. Ten miles away a vehicle, a ship, an aeroplane, a submarine obeys me. It may carry enough of the latest and most powerful explosive that modern science can invent, enough, if exploded, to rival the worst of earthquakes. Yet it obeys my will. It goes where I direct it. It explodes where I want it. And it wipes off the face of the earth anything which I want annihilated.

"That's telautomatics, and that is what has been stolen from our navy and dimly sensed by you clever newspaper men, from whom even the secret service can't quite hide everything. The publication of the rumour alone that the government knows it has lost something has put the secret service in a hole. What might have been done quietly and in a few days has got to be done in the glare of the limelight and with the blare of a brass band—and it has got to be done right away, too. Come on, Walter. I've thrown together all we shall need for one night—and it doesn't include any pajamas, either."

A few minutes later we met our friend Burke of the secret service at the new terminal. He had wired Kennedy earlier in the day saying that he would be in New York and would call him up.

"The plans, as I told you in my message," began Burke, when we had seated ourselves in a compartment of the Pullman, "were those of Captain Shirley, covering the wireless-controlled submarine. The old captain is a thoroughbred, too. I've known him in Washington. Comes of an old New England, family with plenty of money but more brains. For years he has been working on this science of radio-telautomatics, has all kinds of patents, which he has dedicated to the United States, too. Of course the basic, pioneer patents are not his. His work has been in the practical application of them. And, Kennedy, there are some secrets about his latest work that he has not patented; he has given them outright to the Navy Department, because they are too valuable even to patent."

Burke, who liked a good detective tale himself, seemed pleased at holding Kennedy spellbound.

"For instance," he went on, "he has on the bay up here a submarine which can be made into a crewless dirigible. He calls it the Turtle, I believe, because that was the name of the first American submarine built by Dr. Bushnell during the Revolution, even before Fulton."

"You have theories of your own on the case?" asked Craig.

"Well, there are several possibilities. You know there are submarine companies in this country, bitter rivals. They might like to have those plans. Then, too, there are foreign governments."

He paused. Though he said nothing, I felt that there was no doubt what he hinted at. At least one government occurred to me which would like the plans above all others.

"Once some plans of a submarine were stolen, I recall," ruminated Kennedy. "But that theft, I am satisfied, was committed in behalf of a rival company."

"But, Kennedy," exclaimed Burke, "it was bad enough when the plans were stolen. Now Captain Shirley wires me that some one must have tampered with his model. It doesn't work right. He even believes that his own life may be threatened. And there is scarcely a real clue," he added dejectedly. "Of course we are watching all the employes who had access to the draughting-room and tracing everybody who was in the building that night. I have a complete list of them. There are three or four who will bear watching. For instance, there is a young attache of one of the embassies, named Nordheim."

"Nordheim!" I echoed, involuntarily. I had expected an Oriental name.

"Yes, a German. I have been looking up his record, and I find that once he was connected in some way with the famous Titan Iron Works, at Kiel, Germany. We began watching him day before yesterday, but suddenly he disappeared. Then, there is a society woman in Washington, a Mrs. Bayard Brainard, who was at the Department that night. We have been trying to find her. To-day I got word that she was summering in the cottage colony across the bay from Lookout Hill. At any rate, I had to go up there to see the captain, and I thought I'd kill a whole flock of birds with one stone. The chief thought, too, that if you'd take the case with us you had best start on it up there. Next, you will no doubt want to go back to Washington with me."

Lookout Hill was the name of the famous old estate of the Shirleys, on a point of land jutting out into Long Island Sound and with a neighbouring point enclosing a large, deep, safe harbour. On the highest ground of the estate, with a perfect view of both harbour and sound, stood a large stone house, the home of Captain Shirley, of the United States navy, retired.

Captain Shirley, a man of sixty-two or three, bronzed and wiry, met us eagerly.

"So this is Professor Kennedy; I'm glad to meet you, sir," he welcomed, clasping Craig's hand in both of his—a fine figure as he stood erect in the light of the portecochere. "What's the news from Washington, Burke? Any clues?"

"I can hardly tell," replied the secret service man, with assumed cheerfulness. "By the way, you'll have to excuse me for a few minutes while I run back into town on a little errand. Meanwhile, Captain, will you explain to Professor Kennedy just how things are? Perhaps he'd better begin by seeing the Turtle herself."

Burke had not waited longer than to take leave.

"The Turtle," repeated the captain, leading the way into the house. "Well, I did call it that at first. But I prefer to call it the Z99. You know the first submarines, abroad at least, were sometimes called Al, A2, A3, and so on. They were of the diving, plunging type, that is, they submerged on an inclined keel, nose down, like the Hollands. Then came the B type, in which the hydroplane appeared; the C type, in which it was more prominent, and a D type, where submergence is on a perfectly even keel, somewhat like our Lakes. Well, this boat of mine is a last word—the Z99. Call it the Turtle, if you like."

We were standing for a moment in a wide Colonial hall in which a fire was crackling in a huge brick fireplace, taking the chill off the night air.

"Let me give you a demonstration, first," added the captain. "Perhaps
Z99 will work—perhaps not."

There was an air of disappointment about the old veteran as he spoke, uncertainly now, of what a short time ago he had known to be a certainty and one of the greatest it had ever been given the inventive mind of man to know.

A slip of a girl entered from the library, saw us, paused, and was about to turn back. Silhouetted against the curtained door, there was health, animation, gracefulness, in every line of her wavy chestnut hair, her soft, sparkling brown eyes, her white dress and hat to match, which contrasted with the healthy glow of tan on her full neck and arms, and her dainty little white shoes, ready for anything from tennis to tango.

"My daughter Gladys, Professor Kennedy and Mr. Jameson," introduced the captain. "We are going to try the Z99 again, Gladys."

A moment later we four were walking to the edge of the cliff where
Captain Shirley had a sort of workshop and signal-station.

He lighted the gas, for Lookout Hill was only on the edge of the town and boasted gas, electricity, and all modern improvements, as well as the atmosphere of old New England.

"The Z99 is moored just below us at my private dock," began the captain. "I have a shed down there where we usually keep her, but I expected you, and she is waiting, thoroughly overhauled. I have signalled to my men—fellows I can trust, too, who used to be with me in the navy—to cast her off. There—now we are ready."

The captain turned a switch. Instantly a couple of hundred feet below us, on the dark and rippling water, a light broke forth. Another signal, and the light changed.

It was moving.

"The principle of the thing," said Captain Shirley, talking to us but watching the moving light intently, "briefly, is that I use the Hertzian waves to actuate relays on the Z99. That is, I send a child with a message, the grown man, through the relay, so to speak, does the work. So, you see, I can sit up here and send my little David out anywhere to strike down a huge Goliath.

"I won't bore you, yet, with explanations of my radio-combinator, the telecommutator, the aerial coherer relay, and the rest of the technicalities of wireless control of dirigible, self-propelled vessels. They are well known, beginning with pioneers like Wilson and Gardner in England, Roberts in Australia, Wirth and Lirpa in Germany, Gabet in France, and Tesla, Edison, Sims, and the younger Hammond in our own country.

"The one thing, you may not know, that has kept us back while wireless telegraphy has gone ahead so fast is that in wireless we have been able to discard coherers and relays and use detectors and microphones in their places. But in telautomatics we have to keep the coherer. That has been the barrier. The coherer until recently has been spasmodic, until we had Hammond's mercury steel-disc coherer and now my own. Why," he cried, "we are just on the threshold, now, of this great science which Tesla has named telautomatics—the electric arm that we can stretch out through space to do our work and fight our battles."

It was not difficult to feel the enthusiasm of the captain over an invention of such momentous possibilities, especially as the Z99 was well out in the harbour now and we could see her flashing her red and green signal-lights back to us.

"You see," the captain resumed, "I have twelve numbers here on the keys of this radio-combinator—forward, back, stop propeller motor, rudder right, rudder left, stop steering motor, light signals front, light signals rear, launch torpedoes, and so on. The idea is that of a delayed contact. The machinery is always ready, but it delays a few seconds until the right impulse is given, a purely mechanical problem. I take advantage of the delay to have the message repeated by a signal back to me. I can even change it, then. You can see for yourself that it really takes no experience to run the thing when all is going right. Gladys has done it frequently herself. All you have to do is to pay attention, and press the right key for the necessary change. It is when things go wrong that even an expert like myself—confound it—there's something wrong!"

The Z99 had suddenly swerved. Captain Shirley's brow knitted. We gathered around closer, Gladys next to her father and leaning anxiously over the transmitting apparatus.

"I wanted to turn her to port yet she goes to starboard, and signals starboard, too. There—now—she has stopped altogether. What do you think of that?"

Gladys stroked the old seafarer's hand gently, as he sat silently at the table, peering with contracted brows out into the now brilliantly moonlit night.

Shirley looked up at his daughter, and the lines on his face relaxed as though he would hide his disappointment from her eager eyes.

"Confound that light! What's the matter with it?" he exclaimed, changing the subject, and glancing up at the gas-fixture.

Kennedy had already been intently looking at the Welsbach burner overhead, which had been flickering incessantly. "That gas company!" added the Captain, shaking his head in disgust, and showing annoyance over a trivial thing to hide deep concern over a greater, as some men do. "I shall use the electricity altogether after this contract with the company expires. I suppose you literary men, Mr. Jameson, would call that the light that failed."

There was a forced air about his attempt to be facetious that did not conceal, but rather accentuated, the undercurrent of feelings in him.

"On the contrary," broke in Kennedy, "I shouldn't be surprised to find that it is the light that succeeded."

"How do you mean?"

"I wouldn't have said anything about it if you hadn't noticed it yourself. In fact, I may be wrong. It suggests something to me, but it will need a good deal of work to verify it, and then it may not be of any significance. Is that the way the Z99 has behaved always lately?"

"Yes, but I know that she hasn't broken down of herself," Captain Shirley asserted. "It never did before, not since I perfected that new coherer. And now it always does, perhaps fifteen or twenty minutes after I start her out."

Shirley was watching the lights as they serpentined their way to us across the nearly calm water of the bay, idly toying with the now useless combinator.

"Wait here," he said, rising hurriedly. "I must send my motor-boat out there to pick her up and tow her in."

He was gone down the flight of rustic steps on the face of the cliff before we could reply.

"I wish father wouldn't take it to heart so," murmured Gladys. "Sometimes I fear that success or failure of this boat means life or death to him."

"That is exactly why we are here," reassured Kennedy, turning earnestly to her, "to help him to settle this thing at once. This is a beautiful spot," he added, as we stood on the edge of the cliff and looked far out over the tossing waves of the sound.

"What is on that other point?" asked Kennedy, turning again toward the harbour itself.

"There is a large cottage colony there," she replied. "Of course many of the houses are still closed so early in the season, but it is a beautiful place in the summer. The hotel over there is open now, though."

"You must have a lively time when the season is at its height," ventured Kennedy. "Do you know a cottager there, a Mrs. Brainard?"

"Oh, yes, indeed. I have known her in Washington for some time."

"No doubt the cottagers envy you your isolation here," remarked Kennedy, turning and surveying the beautifully kept grounds. "I should think it would be pleasant, too, to have an old Washington friend here."

"It is. We often invite our friends over for lawn-parties and other little entertainments. Mrs. Brainard has just arrived and has only had time to return my first visit to her, but I expect we shall have some good times this summer."

It was evident, at least, that Gladys was not concealing anything about her friend, whether there was any suspicion or not of her.

We had gone into the house to await the return of Captain Shirley. Burke had just returned, his face betraying that he was bursting with news.

"She's here, all right," he remarked in an undertone to Kennedy, "in the Stamford cottage—quite an outfit. French chauffeur, two Japanese servants, maids, and all."

"The Stamford cottage?" repeated Gladys. "Why, that is where Mrs.
Brainard lives."

She gave a startled glance at Kennedy, as she suddenly seemed to realise that both he and the secret-service man had spoken about her friend.

"Yes," said Burke, noting on the instant the perfect innocence of her concern. "What do you know about Mrs. Brainard? Who, where is, Mr. Brainard?"

"Dead, I believe," Gladys hesitated. "Mrs. Brainard has been well known in Washington circles for years. Indeed, I invited her with us the night of the Manila display."

"And Mr. Nordheim?" broke in Burke.

"N-no," she hesitated. "He was there, but I don't know as whose guest."

"Did he seem very friendly with. Mrs. Brainard?" pursued the detective.

I thought I saw a shade of relief pass over her face as she answered, "Yes." I could only interpret it that perhaps Nordheim had been attentive to Gladys herself and that she had not welcomed his attentions.

"I may as well tell you," she said, at length. "It is no secret in our set, and I suppose you would find it out soon, anyhow. It is said that he is engaged to Mrs. Brainard—that is all."

"Engaged?" repeated Burke. "Then that would account for his being at the hotel here. At least, it would offer an excuse."

Gladys was not slow to note the stress that Burke laid on the last word.

"Oh, impossible," she began hurriedly, "impossible that he could have known anything about this other matter. Why, she told me he was to sail suddenly for Germany and came up here for a last visit before he went, and to arrange to come back on his return. Oh, he could know nothing—impossible."

"Why impossible?" persisted Burke. "They have submarines in Germany, don't they? And rival companies, too."

"Who have rival companies?" inquired a familiar voice. It was Captain Shirley, who had returned out of breath from his long climb up the steps from the shore.

"The Germans. I was speaking of an attache named Nordheim."

"Who is Nordheim?" inquired the captain.

"You met him at the Naval building, that night, don't you remember?" replied Gladys.

"Oh, yes, I believe I do—dimly. He was the man who seemed so devoted to Mrs. Brainard."

"I think he is, too, father," she replied hastily. "He has been suddenly called to Berlin and planned to spend the last few days here, at the hotel, so as to be near her. She told me that he had been ordered back to Washington again before he sailed and had had to cut his visit short."

"When did you first notice the interference with the Turtle?" asked
Burke. "I received your message this morning."

"Yesterday morning was the first," replied the captain.

"He arrived the night before and did not leave until yesterday afternoon," remarked Burke.

"And we arrived to-night," put in Craig quietly. "The interference is going on yet."

"Then the Japs," I cut in, at last giving voice to the suspicion I had of the clever little Orientals.

"They could not have stolen the plans," asserted Burke, shaking his head. "No, Nordheim and Mrs. Brainard were the only ones who could have got into the draughting room the night of the Manila celebration."

"Burke," said Kennedy, rising, "I wish you would take me into town. There are a few messages I would like to send. You will excuse us, Captain, for a few hours? Good evening, Miss Shirley." As he bowed I heard Kennedy add to her: "Don't worry about your father. Everything will come out all right soon."

Outside, in the car which Burke had hired, Craig added: "Not to town.
That was an excuse not to alarm Miss Shirley too much over her friend.
Take us over past the Stamford cottage, first."

The Stamford cottage was on the beach, between the shore front and the road. It was not a new place but was built in the hideous style of some thirty years ago with all sorts of little turned and knobby ornaments. We paused down the road a bit, though not long enough to attract attention. There were lights on every floor of the cottage, although most of the neighbouring cottages were dark.

"Well protected by lightning-rods," remarked Kennedy, as he looked the Stamford cottage over narrowly. "We might as well drive on. Keep an eye on the hotel, Burke. It may be that Nordheim intends to return, after all."

"Assuming that he has left," returned the secret-service man.

"But you said he had left," said Kennedy. "What do you mean?"

"I hardly know myself," wearily remarked Burke, on whom the strain of the case, to which we were still fresh, had begun to tell. "I only know that I called up Washington after I heard he had been at the hotel, and no one at our headquarters knew that he had returned. They may have fallen down, but they were to watch both his rooms and the embassy."

"H-m," mused Kennedy. "Why didn't you say that before?"

"Why, I assumed that he had gone back, until you told me there was interference to-night, too. Now, until I can locate him definitely I'm all at sea—that's all."

It was now getting late in the evening, but Kennedy had evidently no intention of returning yet to Lookout Hill. We paused at the hotel, which was in the centre of the cottage colony, and flanked by a hill that ran back of the colony diagonally and from which a view of both the hotel and the cottages could be obtained. Burke's inquiries developed the fact that Nordheim had left very hurriedly and in some agitation. "To tell you the truth," confided the clerk, with whom Burke had ingratiated himself, "I thought he acted like a man who was watched."

Late as it was, Kennedy insisted on motoring to the railroad station and catching the last train to New York. As there seemed to be nothing that I could do at Lookout Hill, I accompanied him on the long and tedious ride, which brought us back to the city in the early hours of the morning.

We stopped just long enough to run up to the laboratory and to secure a couple of little instruments which looked very much like small incandescent lamps in a box. Then, by the earliest train from New York, we returned to Lookout Hill, with only such sleep as Kennedy had predicted, snatched in the day coaches of the trains and during a brief wait in the station.

A half-hour's freshening up with a dip in the biting cold water of the bay, breakfast with Captain Shirley and Miss Gladys, and a return to the excitement of the case, had to serve in place of rest. Burke disappeared, after a hasty conference with Kennedy, presumably to watch Mrs. Brainard, the hotel, and the Stamford cottage to see who went in and out.

"I've had the Z99 brought out of its shed," remarked the captain, as we rose from the breakfast-table. "There was nothing wrong as far as I could discover last night or by a more careful inspection this morning. I'd like to have you take a look at her now, in the daylight."

"I was about to suggest," remarked Kennedy, as we descended the steps to the shore, "that perhaps, first, it might be well to take a short run in her with the crew, just to make sure that there is nothing wrong with the machinery."

"A good idea," agreed the captain.

We came to the submarine, lying alongside the dock and looking like a huge cigar. The captain preceded us down the narrow hatchway, and I followed Craig. The deck was cleared, the hatch closed, and the vessel sealed.