Brixton had evidently been waiting impatiently for our arrival. "Mr. Kennedy?" he inquired, adding quickly without waiting for an answer: "I am glad to see you. I suppose you have noticed the precautions we are taking against intruders? Yet it seems to be all of no avail. I can not be alone even here. If a telephone message comes to me over my private wire, if I talk with my own office in the city, it seems that it is known. I don't know what to make of it. It is terrible. I don't know what to expect next."

Brixton had been standing beside a huge mahogany desk as we entered. I had seen him before at a distance as a somewhat pompous speaker at banquets and the cynosure of the financial district. But there was something different about his looks now. He seemed to have aged, to have grown yellower. Even the whites of his eyes were yellow.

I thought at first that perhaps it might be the effect of the light in the centre of the room, a huge affair set in the ceiling in a sort of inverted hemisphere of glass, concealing and softening the rays of a powerful incandescent bulb which it enclosed. It was not the light that gave him the altered appearance, as I concluded from catching a casual confirmatory glance of perplexity from Kennedy himself.

"My personal physician says I am suffering from jaundice," explained Brixton. Rather than seeming to be offended at our notice of his condition he seemed to take it as a good evidence of Kennedy's keenness that he had at once hit on one of the things that were weighing on Brixton's own mind. "I feel pretty badly, too. Curse it," he added bitterly, "coming at a time when it is absolutely necessary that I should have all my strength to carry through a negotiation that is only a beginning, important not so much for myself as for the whole world. It is one of the first times New York bankers have had a chance to engage in big dealings in that part of the world. I suppose Yvonne has shown you one of the letters I am receiving?"

He rustled a sheaf of them which he drew from a drawer of his desk, and continued, not waiting for Kennedy even to nod:

"Here are a dozen or more of them. I get one or two every day, either here or at my town house or at the office."

Kennedy had moved forward to see them.

"One moment more," Brixton interrupted, still holding them. "I shall come back to the letters. That is not the worst. I've had threatening letters before. Have you noticed this room?"

We had both seen and been impressed by it.

"Let me tell you more about it," he went on. "It was designed especially to be, among other things, absolutely soundproof."

We gazed curiously about the strong room. It was beautifully decorated and furnished. On the walls was a sort of heavy, velvety green wall-paper. Exquisite hangings were draped about, and on the floor were thick rugs. In all I noticed that the prevailing tint was green.

"I had experiments carried out," he explained languidly, "with the object of discovering methods and means for rendering walls and ceilings capable of effective resistance to sound transmission. One of the methods devised involved the use under the ceiling or parallel to the wall, as the case might be, of a network of wire stretched tightly by means of pulleys in the adjacent walls and not touching at any point the surface to be protected against sound. Upon the wire network is plastered a composition formed of strong glue, plaster of Paris, and granulated cork, so as to make a flat slab, between which and the wall or ceiling is a cushion of confined air. The method is good in two respects: the absence of contact between the protective and protected surfaces and the colloid nature of the composition used. I have gone into the thing at length because it will make all the more remarkable what I am about to tell you."

Kennedy had been listening attentively. As Brixton proceeded I had noticed Kennedy's nostrils dilating almost as if he were a hound and had scented his quarry. I sniffed, too. Yes, there was a faint odour, almost as if of garlic in the room. It was unmistakable. Craig was looking about curiously, as if to discover a window by which the odour might have entered. Brixton, with his eyes following keenly every move, noticed him.

"More than that" he added quickly, "I have had the most perfect system of modern ventilation installed in this room, absolutely independent from that in the house."

Kennedy said nothing.

"A moment ago, Mr. Kennedy, I saw you and Mr. Jameson glancing up at the ceiling. Sound-proof as this room is, or as I believe it to be, I—I hear voices, voices from—not through, you understand, but from—that very ceiling. I do not hear them now. It is only at certain times when I am alone. They repeat the words in some of these letters—'You must not take up those bonds. You must not endanger the peace of the world. You will never live to get the interest.' Over and over I have heard such sentences spoken in this very room. I have rushed out and up the corridor. There has been no one there. I have locked the steel door. Still I have heard the voices. And it is absolutely impossible that a human being could get close enough to say them without my knowing and finding out where he is."

Kennedy betrayed by not so much as the motion of a muscle even a shade of a doubt of Brixton's incredible story. Whether because he believed it or because he was diplomatic, Craig took the thing at its face value. He moved a blotter so that he could stand on the top of Brixton's desk in the centre of the room. Then he unfastened and took down the glass hemisphere over the light.

"It is an Osram lamp of about a hundred candlepower, I should judge," he observed.

Apparently he had satisfied himself that there was nothing concealed in the light itself. Laboriously, with such assistance as the memory of Mr. Brixton could give, he began tracing out the course of both the electric light and telephone wires that led down into the den.

Next came a close examination of the ceiling and side walls, the floor, the hangings, the pictures, the rugs, everything. Kennedy was tapping here and there all over the wall, as if to discover whether there was any such hollow sound as a cavity might make. There was none.

A low exclamation from him attracted my attention, though it escaped Brixton. His tapping had raised the dust from the velvety wall-paper wherever he had tried it. Hastily, from a corner where it would not be noticed, he pulled off a piece of the paper and stuffed it into his pocket. Then followed a hasty examination of the intake of the ventilating apparatus.

Apparently satisfied with his examination of things in the den, Craig now prepared to trace out the course of the telephone and light wires in the house. Brixton excused himself, asking us to join him in the library up-stairs after Craig had completed his investigation.

Nothing was discovered by tracing the lines back, as best we could, from the den. Kennedy therefore began at the other end, and having found the points in the huge cellar of the house where the main trunk and feed wires entered, he began a systematic search in that direction.

A separate line led, apparently, to the den, and where this line feeding the Osram lamp passed near a dark storeroom in a corner Craig examined more closely than ever. Seemingly his search was rewarded, for he dived into the dark storeroom and commenced lighting matches furiously to discover what was there.

"Look, Walter," he exclaimed, holding a match so that I could see what he had unearthed. There, in a corner concealed by an old chest of drawers, stood a battery of five storage-cells connected with an instrument that looked very much like a telephone transmitter, a rheostat, and a small transformer coil.

"I suppose this is a direct-current lighting circuit," he remarked, thoughtfully regarding his find. "I think I know what this is, all right. Any amateur could do it, with a little knowledge of electricity and a source of direct current. The thing is easily constructed, the materials are common, and a wonderfully complicated result can be obtained. What's this?"

He had continued to poke about in the darkness as he was speaking. In another corner he had discovered two ordinary telephone receivers.

"Connected up with something, too, by George!" he ejaculated.

Evidently some one had tapped the regular telephone wires running into the house, had run extensions into the little storeroom, and was prepared to overhear everything that was said either to or by those in the house.

Further examination disclosed that there were two separate telephone systems running into Brixton's house. One, with its many extensions, was used by the household and by the housekeeper; the other was the private wire which led, ultimately, down into Brixton's den. No sooner had he discovered it than Kennedy became intensely interested. For the moment he seemed entirely to forget the electric-light wires and became absorbed in tracing out the course of the telephone trunk-line and its extensions. Continued search rewarded him with the discovery that both the household line and the private line were connected by hastily improvised extensions with the two receivers he had discovered in the out-of-the-way corner of a little dark storeroom.

"Don't disturb a thing," remarked Kennedy, cautiously picking up even the burnt matches he had dropped in his hasty search. "We must devise some means of catching the eavesdropper red handed. It has all the marks of being an inside job."

We had completed our investigation of the basement without attracting any attention, and Craig was careful to make it seem that in entering the library we came from the den, not from the cellar. As we waited in the big leather chairs Kennedy was sketching roughly on a sheet of paper the plan of the house, drawing in the location of the various wires.

The door opened. We had expected John Brixton. Instead, a tall, spare foreigner with a close-cropped moustache entered. I knew at once that it must be Count Wachtmann, although I had never seen him.

"Ah, I beg your pardon," he exclaimed in English which betrayed that he had been under good teachers in London. "I thought Miss Brixton was here."

"Count Wachtmann?" interrogated Kennedy, rising.

"The same," he replied easily, with a glance of inquiry at us.

"My friend and I are from the Star" said Kennedy.

"Ah! Gentlemen of the press?" He elevated his eyebrows the fraction of an inch. It was so politely contemptuous that I could almost have throttled him.

"We are waiting to see Mr. Brixton," explained Kennedy.

"What is the latest from the Near East?" Wachtmann asked, with the air of a man expecting to hear what he could have told you yesterday if he had chosen.

There was a movement of the portieres, and a woman entered. She stopped a moment. I knew it was Miss Brixton. She had recognised Kennedy, but her part was evidently to treat him as a total stranger.

"Who are these men, Conrad?" she asked, turning to Wachtmann.

"Gentlemen of the press, I believe, to see your father, Yvonne," replied the count.

It was evident that it had not been mere newspaper talk about this latest rumored international engagement.

"How did you enjoy it?" he asked, noticing the title of a history which she had come to replace in the library.

"Very well—all but the assassinations and the intrigues," she replied with a little shudder.

He shot a quick, searching look at her face. "They are a violent people—some of them," he commented quickly.

"You are going into town to-morrow?" I heard him ask Miss Brixton, as they walked slowly down the wide hall to the conservatory a few moments later.

"What do you think of him?" I whispered to Kennedy.

I suppose my native distrust of his kind showed through, for Craig merely shrugged his shoulders. Before he could reply Mr. Brixton joined us.

"There's another one—just came," he ejaculated, throwing a letter down on the library table. It was only a few lines this time:

"The bonds will not be subject to a tax by the government, they say. No—because if there is a war there won't be any government to tax them!"

The note did not appear to interest Kennedy as much as what he had discovered. "One thing is self-evident, Mr. Brixton," he remarked. "Some one inside this house is spying, is in constant communication with a person or persons outside. All the watchmen and Great Danes on the estate are of no avail against the subtle, underground connection that I believe exists. It is still early in the afternoon. I shall make a hasty trip to New York and return after dinner. I should like to watch with you in the den this evening."

"Very well," agreed Brixton. "I shall arrange to have you met at the station and brought here as secretly as I can."

He sighed, as if admitting that he was no longer master of even his own house.

Kennedy was silent during most of our return trip to New York. As for myself, I was deeply mired in an attempt to fathom Wachtmann. He baffled me. However, I felt that if there was indeed some subtle, underground connection between some one inside and someone outside Brixton's house, Craig would prepare an equally subtle method of meeting it on his own account. Very little was said by either of us on the journey up to the laboratory, or on the return to Woodrock. I realised that there was very little excuse for a commuter not to be well informed. I, at least, had plenty of time to exhaust the newspapers I had bought.

Whether or not we returned without being observed, I did not know, but at least we did find that the basement and dark storeroom were deserted, as we cautiously made our way again it to the corner where Craig had made his enigmatical discoveries of the afternoon.

While I held a pocket flashlight Craig was busy concealing another instrument of his own in the little storeroom. It seemed to be a little black disk about as big as a watch, with a number of perforated holes in one face. Carelessly he tossed it into the top drawer of the chest under some old rubbish, shut the drawer tight and ran a flexible wire out of the back of the chest. It was a simple matter to lay the wire through some bins next the storeroom and then around to the passageway down to the subterranean den of Brixton. There Craig deposited a little black box about the size of an ordinary kodak.

For an hour or so we sat with Brixton. Neither of us said anything, and
Brixton was uncommunicatively engaged in reading a railroad report.
Suddenly a sort of muttering, singing noise seemed to fill the room.

"There it is!" cried Brixton, clapping the book shut and looking eagerly at Kennedy.

Gradually the sound increased in pitch. It seemed to come from the ceiling, not from any particular part of the room, but merely from somewhere overhead. There was no hallucination about it. We all heard. As the vibrations increased it was evident that they were shaping themselves into words.

Kennedy had grasped the black box the moment the sound began and was holding two black rubber disks to his ears.

At last the sound from overhead became articulate It was weird, uncanny. Suddenly a voice said distinctly: "Let American dollars beware. They will not protect American daughters."

Craig had dropped the two ear-pieces and was gazing intently at the
Osram lamp in the ceiling. Was he, too, crazy?

"Here, Mr. Brixton, take these two receivers of the detectaphone," said
Kennedy. "Tell me whether you can recognise the voice."

"Why, it's familiar," he remarked slowly. "I can't place it, but I've heard it before. Where is it? What is this thing, anyhow?"

"It is someone hidden in the storeroom in the basement," answered
Craig. "He is talking into a very sensitive telephone transmitter and—"

"But the voice—here?" interrupted Brixton impatiently.

Kennedy pointed to the incandescent lamp in the ceiling. "The incandescent lamp," he said, "is not always the mute electrical apparatus it is supposed to be. Under the right conditions it can be made to speak exactly as the famous 'speaking-arc,' as it was called by Professor Duddell, who investigated it. Both the arc-light and the metal-filament lamp can be made to act as telephone receivers."

It seemed unbelievable, but Kennedy was positive. "In the case of the speaking-arc or 'arcophone,' as it might be called," he continued, "the fact that the electric arc is sensitive to such small variations in the current over a wide range of frequency has suggested that a direct-current arc might be used as a telephone receiver. All that is necessary is to superimpose a microphone current on the main arc current, and the arc reproduces sounds and speech distinctly, loud enough to be heard several feet. Indeed, the arc could be used as a transmitter, too, if a sensitive receiver replaced the transmitter at the other end. The things needed are an arc-lamp, an impedance coil, or small transformer-coil, a rheostat, and a source of energy. The alternating current is not adapted to reproduce speech, but the ordinary direct current is. Of course, the theory isn't half as simple as the apparatus I have described."

He had unscrewed the Osram lamp. The talking ceased immediately.

"Two investigators named Ort and Ridger have used a lamp like this as a receiver," he continued. "They found that words spoken were reproduced in the lamp. The telephonic current variations superposed on the current passing through the lamp produce corresponding variations of heat in the filament, which are radiated to the glass of the bulb, causing it to expand and contract proportionately, and thus transmitting vibrations to the exterior air. Of course, in sixteen-and thirty-two-candle-power lamps the glass is too thick, and the heat variations are too feeble."

Who was it whose voice Brixton had recognised as familiar over Kennedy's hastily installed detectaphone? Certainly he must have been a scientist of no mean attainment. That did not surprise me, for I realised that from that part of Europe where this mystical Red Brotherhood operated some of the most famous scientists of the world had sprung.

A hasty excursion into the basement netted us nothing. The place was deserted.

We could only wait. With parting instructions to Brixton in the use of the detectaphone we said good night, were met by a watchman and escorted as far as the lodge safely.

Only one remark did Kennedy make as we settled ourselves for the long ride in the accommodation train to the city. "That warning means that we have two people to protect—both Brixton and his daughter."

Speculate as I might, I could find no answer to the mystery, nor to the question, which was also unsolved, as to the queer malady of Brixton himself, which his physician diagnosed as jaundice.