Karatoff faced Kennedy squarely. There was an air almost of triumph in his eyes. "I think I had better say no more, except under the advice of my lawyer," he remarked, finally. "When the police want me, they can find me here."

Quite evident to me now, as we went out of the studio, was the fact that Karatoff considered himself a martyr, that he was not only the victim of an accident, but of persecution as well.

"The fishing was good," remarked Kennedy, tersely, as we reached the street. "Now before I see Errol I should like to see Gaines again."

I tried to reason it out as we walked along in silence. Marchant had known Edith Gaines intimately. Carita Belleville had known Errol as well. I recalled Errol hovering about Mrs. Gaines at the tea and the incident during the seance when Carita Belleville had betrayed her annoyance over some remark by Errol. The dancing by Edith Gaines had given a flash of the jealous nature of the woman. Had it been interest in Errol that had led her to visit the laboratory? Kennedy was weaving a web about some one, I knew. But about whom?

As we pa.s.sed a corner, he paused, entered a drugstore and called up several numbers at a pay-station telephone booth. Then we turned into the campus and proceeded rapidly toward the laboratory of the psychological department. Gaines was there, sitting at his desk, writing, as we entered.

"I'm glad to see you," he greeted, laying down his work. "I am just finishing the draft of my report on that Karatoff affair. I have been trying to reach you by telephone to know whether you would add anything to it. Is there anything new?"

"Yes," returned Kennedy, "there is something new. I've just come from Karatoff's and on the way I decided suddenly that it was time we did something. So I have called up, and the police will bring Errol here, as well as Miss Belleville. Karatoff will come--he won't dare stay away; and I also took the liberty of calling Mrs. Gaines."

"To come here?" repeated Gaines, in mild surprise. "All of them?"

"Yes. I hope you will pardon me for intruding, but I want to borrow some of your psychological laboratory apparatus, and I thought the easiest way would be to use it here rather than take it all over to my place and set it up again."

"I'm sure everything is at your service," offered Gaines. "It's a little unexpected, but if the others can stand the chaotic condition of the room, I guess we can."

Kennedy had been running his eye over the various instruments which Gaines and his students used in their studies, and was now examining something in a corner on a little table. It was a peculiar affair, quite simple, but conveying to me no idea of its use. There seemed to be a cuff, a gla.s.s chamber full of water into which it fitted, tubes and wires that attached various dials and recording instruments to the chamber, and what looked like a chronograph.

"That is my new plethysmograph," remarked Gaines, noting with some satisfaction how Kennedy had singled it out.

"I've heard the students talk of it," returned Kennedy. "It's an improved apparatus, Walter, that records one's blood flow." I nodded politely and concealed my ignorance in a discreet silence, hoping that Gaines would voluntarily enlighten us.

"One of my students is preparing an exhaustive table," went on Gaines, as I had hoped, "showing the effects on blood distribution of different stimuli--for instance, cold, heat, chloroform, arenalin, desire, disgust, fear; physical conditions, drugs, emotions--all sorts of things can be studied by this plethysmograph which can be set to record blood flow through the brain, the extremities, any part of the body.

When the thing is charted I think we shall have opened up a new field."

"Certainly a very promising one for me," put in Kennedy. "How has this machine been improved? I've seen the old ones, but this is the first time I've seen this. How does it work?"

"Well," explained Gaines, with just a touch of pride, "you see, for studying blood flow in the extremities, I slip this cuff over my arm, we'll say. Suppose it is the effect of pain I want to study. Just jab that needle in my other arm. Don't mind. It's in the interest of science. See, when I winced then, the plethysmograph recorded it. It smarts a bit and I'm trying to imagine it smarts worse. You'll see how pain affects blood flow."

As he watched the indicator, Kennedy asked one question after another about the working of the machine, and the manner in which the modern psychologist was studying every emotion.

"By the way, Walter," he interrupted, glancing at his watch, "call up and see if they've started with Errol and the rest yet. Don't stop, Gaines. I must understand this thing before they get here. It's just the thing I want."

"I should be glad to let you have it, then," replied Gaines.

"I think I'll need something new with these people," went on Kennedy.

"Why, do you know what I've discovered?"

"No, but I hope it's something I can add to my report?"

"Perhaps. We'll see. In the first place, I found that digitalis had been put in Marchant's tea."

"They'll be here directly," I reported from the telephone, hanging it up and joining them again.

"It couldn't have been an accident, as Karatoff said," went on Kennedy, rapidly. "The drug increased the blood pressure of Marchant, who was already suffering from hardening of the arteries. In short, it is my belief that the episode of the rubber dagger was deliberately planned, an elaborate scheme to get Marchant out of the way. No one else seems to have noticed it, but those slips of paper on which we all wrote have disappeared. At the worst, it would look like an accident, Karatoff would be blamed, and--" There was a noise outside as the car pulled up.

"Here, let me take this off before any of them see it," whispered Gaines, removing the cuff, just as the door opened and Errol and Karatoff, Carita Belleville and Edith Gaines entered.

Before even a word of greeting pa.s.sed, Kennedy stepped forward. "It was NOT an accident," he repeated. "It was a deliberately planned, apparently safe means of revenge on Marchant, the lover of Mrs. Gaines.

Without your new plethysmograph, Gaines, you might have thrown it on an innocent person!"

X

THE SUBMARINE MINE

"Here's the bullet. What I want you to do, Professor Kennedy, is to catch the crank who fired it."

Capt. Lansing Marlowe, head of the new American Shipbuilding Trust, had summoned us in haste to the Belleclaire and had met us in his suite with his daughter Marjorie. Only a glance was needed to see that it was she, far more than her father, who was worried.

"You must catch him," she appealed. "Father's life is in danger. Oh, you simply MUST."

I knew Captain Marlowe to be a proverbial fire-eater, but in this case, at least, he was no alarmist. For, on the table, as he spoke, he laid a real bullet.

Marjorie Marlowe shuddered at the mere sight of it and glanced apprehensively at him as if to rea.s.sure herself. She was a tall, slender girl, scarcely out of her teens, whose face was one of those quite as striking for its character as its beauty. The death of her mother a few years before had placed on her much of the responsibility of the captain's household and with it a charm added to youth.

More under the spell of her plea than even Marlowe's vigorous urging, Kennedy, without a word, picked up the bullet and examined it. It was one of the modern spitzer type, quite short, conical in shape, tapering gradually, with the center of gravity back near the base.

"I suppose you know," went on the captain, eagerly, "that our company is getting ready to-morrow to launch the Usona, the largest liner that has ever been built on this side of the water--the name is made up of the initials of the United States of North America.

"Just now," he added, enthusiastically, "is what I call the golden opportunity for American shipping. While England and Germany are crippled, it's our chance to put the American flag on the sea as it was in the old days, and we're going to do it. Why, the shipyards of my company are worked beyond their capacity now."

Somehow the captain's enthusiasm was contagious. I could see that his daughter felt it, that she was full of fire over the idea. But at the same time something vastly more personal weighed on her mind.

"But, father," she interrupted, anxiously, "tell them about the BULLET."

The captain smiled indulgently as though he would say that he was a tough old bird to wing. It was only a mask to hide the fighting spirit underneath.

"We've had nothing but trouble ever since we laid the keel of that ship," he continued, pugnaciously, "strikes, a fire in the yard, delays, about everything that could happen. Lately we've noticed a motor-boat hanging about the river-front of the yards. So I've had a boat of my own patrolling the river."

"What sort of craft is this other?" inquired Kennedy, interested at once.

"A very fast one--like those express cruisers that we hear so much about now."

"Whose is it? Who was in it? Have you any idea?"

Marlowe shook his head doubtfully. "No idea. I don't know who owns the boat or who runs it. My men tell me they think they've seen a woman in it sometimes, though. I've been trying to figure it out. Why should it be hanging about? It can't be spying. There isn't any secrecy about the Usona. Why is it? It's a mystery."

"And the shot?" prompted Craig, tapping the bullet.

"Oh yes, let me tell you. Last night, Marjorie and I arrived from Bar Harbor on my yacht, for the launching. It's anch.o.r.ed off the yard now.

Well, early this morning, while it was still gray and misty, I was up.

I'll confess I'm worried over to-morrow. I hadn't been able to forget that cruiser. I was out on the deck, peering into the mist, when I'm sure I saw her. I was just giving a signal to the boat we have patrolling, when a shot whistled past me and the bullet buried itself in the woodwork of the main saloon back of me. I dug it out of the wood with my knife--so you see I got it almost unflattened. That's all I have got, too. The cruiser made a getaway, clean."