As I watched I could not escape observing that Miss Lowe followed Burke furtively now, as though he had some uncanny power.
Fortescue's laboratory was in an old building on a side street several blocks from the main thoroughfares of Manhattan. He had evidently chosen it, partly because of its very inaccessibility in order to secure the quiet necessary for his work.
"If he had any visitors last night," commented Kennedy when our cab at last pulled up before the place, "they might have come and gone unnoticed."
We entered. Nothing had been disturbed in the laboratory by the coroner and Kennedy was able to gain a complete idea of the case rapidly, almost as well as if we had been called in immediately.
Fortescue's body, it seemed, had been discovered sprawled out in a big armchair, as Burke had said, by one of his assistants only a few hours before when he had come to the laboratory in the morning to open it. Evidently he had been there undisturbed all night, keeping a gruesome vigil over his looted treasure house.
As we gleaned the meager facts, it became more evident that whoever had perpetrated the crime must have had the diabolical cunning to do it in some ordinary way that aroused no suspicion on the part of the victim, for there was no sign of any violence anywhere.
As we entered the laboratory, I noted an involuntary shudder on the part of Paula Lowe, but, as far as I knew, it was no more than might have been felt by anyone under the circumstances.
Fortescue's body had been removed from the chair in which it had been found and lay on a couch at the other end of the room, covered merely by a sheet. Otherwise, everything, even the armchair, was undisturbed.
Kennedy pulled back a corner of the sheet, disclosing the face, contorted and of a peculiar, purplish hue from the congested blood vessels. He bent over and I did so, too. There was an unmistakable odor of tobacco on him. A moment Kennedy studied the face before us, then slowly replaced the sheet.
Miss Lowe had paused just inside the door and seemed resolutely bound not to look at anything. Kennedy meanwhile had begun a most minute search of the table and floor of the laboratory near the spot where the armchair had been sitting.
In my effort to glean what I could from her actions and expressions I did not notice that Craig had dropped to his knees and was peering into the shadow under the laboratory table. When at last he rose and straightened himself up, however, I saw that he was holding in the palm of his hand a half-smoked, gold-tipped cigarette, which had evidently fallen on the floor beneath the table where it had burned itself out, leaving a blackened mark on the wood.
An instant afterward he picked out from the pile of articles found in Fortescue's pockets and lying on another table a silver cigarette case. He snapped it open. Fortescue's cigarettes, of which there were perhaps a half dozen in the case, were cork- tipped.
Some one had evidently visited the inventor the night before, had apparently offered him a cigarette, for there were any number of the cork-tipped stubs lying about. Who was it? I caught Paula looking with fascinated gaze at the gold-tipped stub, as Kennedy carefully folded it up in a piece of paper and deposited it in his pocket. Did she know something about the case, I wondered?
Without a word, Kennedy seemed to take in the scant furniture of the laboratory at a glance and a quick step or two brought him before a steel filing cabinet. One drawer, which had not been closed as tightly as the rest, projected a bit. On its face was a little typewritten card bearing the inscription: "E-M GUN."
He pulled the drawer open and glanced over the data in it.
"Just what is an electro-magnetic gun?" I asked, interpreting the initials on the drawer.
"Well," he explained as he turned over the notes and sketches, "the primary principle involved in the construction of such a gun consists in impelling the projectile by the magnetic action of a solenoid, the sectional coils or helices of which are supplied with current through devices actuated by the projectile itself. In other words, the sections of helices of the solenoid produce an accelerated motion of the projectile by acting successively on it, after a principle involved in the construction of electro-magnetic rock drills and dispatch tubes.
"All projectiles used in this gun of Fortescue's evidently must have magnetic properties and projectiles of iron or containing large portions of iron are necessary. You see, many coils are wound around the barrel of the gun. As the projectile starts it does so under the attraction of those coils ahead which the current makes temporary magnets. It automatically cuts off the current from those coils that it passes, allowing those further on only to attract it, and preventing those behind from pulling it back."
He paused to study the scraps of plans. "Fortescue had evidently also worked out a way of changing the poles of the coils as the projectile passed, causing them then to repel the projectile, which must have added to its velocity. He seems to have overcome the practical difficulty that in order to obtain service velocities with service projectiles an enormous number of windings and a tremendously long barrel are necessary as well as an abnormally heavy current beyond the safe carrying capacity of the solenoid which would raise the temperature to a point that would destroy the coils."
He continued turning over the prints and notes in the drawer. When he finished, he looked up at us with an expression that indicated that he had merely satisfied himself of something he had already suspected.
"You were right, Burke," he said. "The final plans are gone."
Burke, who, in the meantime, had been telephoning about the city in a vain effort to locate Baron Kreiger, both at such banking offices in Wall Street as he might be likely to visit and at some of the hotels most frequented by foreigners, merely nodded. He was evidently at a loss completely how to proceed.
In fact, there seemed to be innumerable problems--to warn Baron Kreiger, to get the list of the assassinations, to guard Miss Lowe against falling into the hands of her anarchist friends again, to find the murderer of Fortescue, to prevent the use of the electro- magnetic gun, and, if possible, to seize the anarchists before they had a chance to carry further their plans.
"There is nothing more that we can do here," remarked Craig briskly, betraying no sign of hesitation. "I think the best thing we can do is to go to my own laboratory. There at least there is something I must investigate sooner or later."
No one offering either a suggestion or an objection, we four again entered our cab. It was quite noticeable now that the visit had shaken Paula Lowe, but Kennedy still studiously refrained from questioning her, trusting that what she had seen and heard, especially Burke's report as to Baron Kreiger, would have its effect.
Like everyone visiting Craig's laboratory for the first time, Miss Lowe seemed to feel the spell of the innumerable strange and uncanny instruments which he had gathered about him in his scientific warfare against crime. I could see that she was becoming more and more nervous, perhaps fearing even that in some incomprehensible way he might read her own thoughts. Yet one thing I did not detect. She showed no disposition to turn back on the course on which she had entered by coming to us in the first place.
Kennedy was quickly and deftly testing the stub of the little thin, gold-tipped cigarette.
"Excessive smoking," he remarked casually, "causes neuroses of the heart and tobacco has a specific affinity for the coronary arteries as well as a tremendous effect on the vagus nerve. But I don't think this was any ordinary smoke."
He had finished his tests and a quiet smile of satisfaction flitted momentarily over his face. We had been watching him anxiously, wondering what he had found.
As he looked up he remarked to us, with his eyes fixed on Miss Lowe, "That was a ladies' cigarette. Did you notice the size? There has been a woman in this case--presumably."
The girl, suddenly transformed by the rapid-fire succession of discoveries, stood before us like a specter.