We had by this time swung around to the side of the houseboat. I realized as we mounted the ladder that the marine gasoline engine had materially changed the old-time houseboat from a mere scow or barge with a low flat house on it, moored in a bay or river, and only with difficulty and expense towed from one place to another. Now the houseboat was really a fair-sized yacht.

The Lucie was built high in order to give plenty of accommodation for the living quarters. The staterooms, dining rooms and saloon were really rooms, with seven or eight feet of head room, and furnished just as one would find in a tasteful and expensive house.

Down in the hull, of course, was the gasoline motor which drove the propeller, so that when the owner wanted a change of scene all that was necessary was to get up anchor, start the motor and navigate the yacht-houseboat to some other harbor.

Edwards himself met us on the deck. He was a tall man, with a red face, a man of action, of outdoor life, apparently a hard worker and a hard player. It was quite evident that he had been waiting for the return of Waldon anxiously.

"You find us considerably upset, Professor Kennedy," he greeted Craig, as his brother-in-law introduced us.

Edwards turned and led the way toward the saloon. As he entered and bade us be seated in the costly cushioned wicker chairs I noticed how sumptuously it was furnished, and particularly its mechanical piano, its phonograph and the splendid hardwood floor which seemed to invite one to dance in the cool breeze that floated across from one set of open windows to the other. And yet in spite of everything, there was that indefinable air of something lacking, as in a house from which the woman is gone.

"You were not here last night, I understand," remarked Kennedy, taking in the room at a glance.

"Unfortunately, no," replied Edwards, "Business has kept me with my nose pretty close to the grindstone this summer. Waldon called me up in the middle of the night, however, and I started down in my car, which enabled me to get here before the first train. I haven't been able to do a thing since I got here except just wait—wait—wait. I confess that I don't know what else to do. Waldon seemed to think we ought to have some one down here—and I guess he was right. Anyhow, I'm glad to see you."

I watched Edwards keenly. For the first time I realized that I had neglected to ask Waldon whether he had seen the unfinished letter. The question was unnecessary. It was evident that he had not.

"Let me see, Waldon, if I've got this thing straight," Edwards went on, pacing restlessly up and down the saloon. "Correct me if I haven't. Last night, as I understand it, there was a sort of little family party here, you and Miss Verrall and your mother from the Nautilus, and Mrs. Edwards and Dr. Jermyn."

"Yes," replied Waldon with, I thought, a touch of defiance at the words "family party." He paused as if he would have added that the Nautilus would have been more congenial, anyhow, then added, "We danced a little bit, all except Lucie. She said she wasn't feeling any too well."

Edwards had paused by the door. "If you'll excuse me a minute," he said, "I'll call Jermyn and Mrs. Edwards' maid, Juanita. You ought to go over the whole thing immediately, Professor Kennedy."

"Why didn't you say anything about the letter to him?" asked Kennedy under his breath.

"What was the use?" returned Waldon. "I didn't know how he'd take it. Besides, I wanted your advice on the whole thing. Do you want to show it to him?"

"Perhaps it's just as well," ruminated Kennedy. "It may be possible to clear the thing up without involving anybody's name. At any rate, some one is coming down the passage this way."

Edwards entered with Dr. Jermyn, a clean-shaven man, youthful in appearance, yet approaching middle age. I had heard of him before. He had studied several years abroad and had gained considerable reputation since his return to America.

Dr. Jermyn shook hands with us cordially enough, made some passing comment on the tragedy, and stood evidently waiting for us to disclose our hands.

"You have been Mrs. Edwards' physician for some time, I believe?" queried Kennedy, fencing for an opening.

"Only since her marriage," replied the doctor briefly.

"She hadn't been feeling well for several days, had she?" ventured
Kennedy again.

"No," replied Dr. Jermyn quickly. "I doubt whether I can add much to what you already know. I suppose Mr. Waldon has told you about her illness. The fact is, I suppose her maid Juanita will be able to tell you really more than I can."

I could not help feeling that Dr. Jermyn showed a great deal of reluctance in talking.

"You have been with her several days, though, haven't you?"

"Four days, I think. She was complaining of feeling nervous and telegraphed me to come down here. I came prepared to stay over night, but Mr. Edwards happened to run down that day, too, and he asked me if I wouldn't remain longer. My practice in the summer is such that I can easily leave it with my assistant in the city, so I agreed. Really, that is about all I can say. I don't know yet what was the matter with Mrs. Edwards, aside from the nervousness which seemed to be of some time standing."

He stood facing us, thoughtfully stroking his chin, as a very pretty and petite maid nervously entered and stood facing us in the doorway.

"Come in, Juanita," encouraged Edwards. "I want you to tell these gentlemen just what you told me about discovering that Madame had gone—and anything else that you may recall now."

"It was Juanita who discovered that Madame was gone, you know," put in
Waldon.

"How did you discover it?" prompted Craig.

"It was very hot," replied the maid, "and often on hot nights I would come in and fan Madame since she was so wakeful. Last night I went to the door and knocked. There was no reply. I called to her, 'Madame, madame.' Still there was no answer. The worst I supposed was that she had fainted. I continued to call."

"The door was locked?" inquired Kennedy.

"Yes, sir. My call aroused the others on the boat. Dr. Jermyn came and he broke open the door with his shoulder. But the room was empty. Madame was gone."

"How about the windows?" asked Kennedy.

"Open. They were always open these nights. Sometimes Madame would sit by the window when there was not much breeze."

"I should like to see the room," remarked Craig, with an inquiring glance at Edwards.

"Certainly," he answered, leading the way down a corridor.

Mrs. Edwards' room was on the starboard side, with wide windows instead of portholes. It was furnished magnificently and there was little about it that suggested the nautical, except the view from the window.

"The bed had not been slept in," Edwards remarked as we looked about curiously.

Kennedy walked over quickly to the wide series of windows before which was a leather-cushioned window seat almost level with the window, several feet above the level of the water. It was by this window, evidently, that Juanita meant that Mrs. Edwards often sat. It was a delightful position, but I could readily see that it would be comparatively easy for anyone accidentally or purposely to fall.

"I think myself," Waldon remarked to Kennedy, "that it must have been from the open window that she made her way to the outside. It seems that all agree that the door was locked, while the window was wide open."

"There had been no sound—no cry to alarm you?" shot out Kennedy suddenly to Juanita.

"No, sir, nothing. I could not sleep myself, and I thought of Madame."

"You heard nothing?" he asked of Dr. Jermyn.

"Nothing until I heard the maid call," he replied briefly.

Mentally I ran over again Kennedy's first list of possibilities—taken off by another boat, accident, drugs, suicide, murder.

Was there, I asked myself, sufficient reason for suicide? The letter seemed to me to show too proud a spirit for that. In fact the last sentence seemed to show that she was contemplating the surest method of revenge, rather than surrender. As for accident, why should a person fall overboard from a large houseboat into a perfectly calm harbor? Then, too, there had been no outcry. Somehow, I could not seem to fit any of the theories in with the facts. Evidently it was like many another case, one in which we, as yet, had insufficient data for a conclusion.

Suddenly I recalled the theory that Waldon himself had advanced regarding the wireless, either from the boat itself or from the wireless station. For the moment, at least, it seemed plausible that she might have been seated at the window, that she might have been affected by escaped wireless, or by electrolysis. I knew that some physicians had described a disease which they attributed to wireless, a sort of anemia with a marked diminution in the number of red corpuscles in the blood, due partly to the over etherization of the air by reason of the alternating currents used to generate the waves.

"I should like now to inspect the little wireless plant you have here on the Lucie," remarked Kennedy. "I noticed the mast as we were approaching a few minutes ago."

I had turned at the sound of his voice in time to catch Edwards and Dr. Jermyn eyeing each other furtively. Did they know about the letter, after all, I wondered? Was each in doubt about just how much the other knew?

There was no time to pursue these speculations. "Certainly," agreed Mr.
Edwards promptly, leading the way.

Kennedy seemed keenly interested in inspecting the little wireless plant, which was of a curious type and not exactly like any that I had seen before.

"Wireless apparatus," he remarked, as he looked it over, "is divided into three parts, the source of power whether battery or dynamo, the making and sending of wireless waves, including the key, spark, condenser and tuning coil, and the receiving apparatus, head telephones, antennae, ground and detector."

Pedersen, the engineer, came in while we were looking the plant over, but seemed uncommunicative to all Kennedy's efforts to engage him in conversation.

"I see," remarked Kennedy, "that it is a very compact system with facilities for a quick change from one wave length to another."

"Yes," grunted Pedersen, as averse to talking, evidently, as others on the Lucie.

"Spark gap, quenched type," I heard Kennedy mutter almost to himself, with a view to showing Pedersen that he knew something about it. "Break system relay—operator can overhear any interference while transmitting—transformation by a single throw of a six-point switch which tunes the oscillating and open circuits to resonance. Very clever—very efficient. By the way, Pedersen, are you the only person aboard who can operate this?"

"How should I know?" he answered almost surlily.

"You ought to know, if anybody," answered Kennedy unruffled. "I know that it has been operated within the past few days."

Pedersen shrugged his shoulders. "You might ask the others aboard," was all he said. "Mr. Edwards pays me to operate it only for himself, when he has no other operator."

Kennedy did not pursue the subject, evidently from fear of saying too much just at present.

"I wonder if there is anyone else who could have operated it," said
Waldon, as we mounted again to the deck.

"I don't know," replied Kennedy, pausing on the way up. "You haven't a wireless on the Nautilus, have you?"

Waldon shook his head. "Never had any particular use for it myself," he answered.

"You say that Miss Verrall and her mother have gone back to the city?" pursued Kennedy, taking care that as before the others were out of earshot.

"Yes."

"I'd like to stay with you tonight, then," decided Kennedy. "Might we go over with you now? There doesn't seem to be anything more I can do here, unless we get some news about Mrs. Edwards."

Waldon seemed only too glad to agree, and no one on the Lucie insisted on our staying.

We arrived at the Nautilus a few minutes later, and while we were lunching Kennedy dispatched the tender to the Marconi station with a note.

It was early in the afternoon when the tender returned with several packages and coils of wire. Kennedy immediately set to work on the Nautilus stretching out some of the wire.

"What is it you are planning?" asked Waldon, to whom every action of
Kennedy seemed to be a mystery of the highest interest.

"Improvising my own wireless," he replied, not averse to talking to the young man to whom he seemed to have taken a fancy. "For short distances, you know, it isn't necessary to construct an aerial pole or even to use outside wires to receive messages. All that is needed is to use just a few wires stretched inside a room. The rest is just the apparatus."

I was quite as much interested as Waldon. "In wireless," he went on, "the signals are not sent in one direction, but in all, so that a person within range of the ethereal disturbance can get them if only he has the necessary receiving apparatus. This apparatus need not be so elaborate and expensive as used to be thought needful if a sensitive detector is employed, and I have sent over to the station for a new piece of apparatus which I knew they had in almost any Marconi station. Why, I've got wireless signals using only twelve feet of number eighteen copper wire stretched across a room and grounded with a water pipe. You might even use a wire mattress on an iron bedstead."

"Can't they find out by—er, interference?" I asked, repeating the term
I had so often heard.

Kennedy laughed. "No, not for radio apparatus which merely receives radiograms and is not equipped for sending. I am setting up only one side of a wireless outfit here. All I want to do is to hear what is being said. I don't care about saying anything."

He unwrapped another package which had been loaned to him by the radio station and we watched him curiously as he tested it and set it up. Some parts of it I recognized such as the very sensitive microphone, and another part I could have sworn was a phonograph cylinder, though Craig was so busy testing his apparatus that now we could not ask questions.

It was late in the afternoon when he finished, and we had just time to run up to the dock at Seaville and stop off at the Lucie to see if anything had happened in the intervening hours before dinner. There was nothing, except that I found time to file a message to the Star and meet several fellow newspaper men who had been sent down by other papers on the chance of picking up a good story.

We had the Nautilus to ourselves, and as she was a very comfortable little craft, we really had a very congenial time, a plunge over her side, a good dinner, and then a long talk out on deck under the stars, in which we went over every phase of the case. As we discussed it, Waldon followed keenly, and it was quite evident from his remarks that he had come to the conclusion that Dr. Jermyn at least knew more than he had told about the case.

Still, the day wore away with no solution yet of the mystery.