Kennedy, by this time, had started the engine. MacLeod placed the bright little songster near the stove on the work-bench and began to watch it narrowly.
More than ever up in the air over the mystery, I could only watch Kennedy and MacLeod, each following his own lines.
It might, perhaps, have been ten minutes after MacLeod returned, and during that time he had never taken his eyes off the bird, when I began to feel a little drowsy. A word from MacLeod roused me.
“There’s carbon monoxide in the air, Kennedy!” he exclaimed. “You know how this gas affects birds.”
Kennedy looked over intently. The canary had begun to show evident signs of distress over something.
“It must be that this stove is defective,” pursued MacLeod, picking up the poor little bird and carrying it quickly into the fresh air, where it could regain its former liveliness. Then, when he returned, he added, “There must be some defect in the stove or the draught that makes it send out the poisonous gas.”
“There’s some gas,” agreed Kennedy. “It must have cleared away mostly, though, or we couldn’t stand it ourselves.”
Craig continued to look about the car and the building, in the vain hope of discovering some other clue. Had Mrs. Snedden been killed by the carbonic oxide? Was it a case of gas poisoning? Then, too, why had she been here at all? Who had shut her up? Had she been overcome first and, in a stupor, been unable to move to save herself? Above all, what had this to do with the mysterious phantom slayer that had wrecked so much of the works in less than a week?
It was quite late in the afternoon when, at last, people came from the town and took away both the body of Mrs. Snedden and Jackson’s car. Snedden could only stare and work his fingers, and after we had seen him safely in the care of some one we could trust Kennedy, MacLeod, and I climbed into MacLeod’s car silently.
“It’s too deep for me,” acknowledged MacLeod. “What shall we do next?”
“Surely that fellow must have my pictures developed by this time,” considered Kennedy. “Shoot back there.”
“They came out beautifully—all except one,” reported the druggist, who was somewhat of a camera fiend himself. “That’s a wonderful system, sir.”
Kennedy thanked him for his trouble and took the prints. With care he pieced them together, until he had several successive panoramas of the country taken from various elevations of the parachute. Then, with a magnifying-glass, he went over each section minutely.
“Look at that!” he pointed out at last with the sharp tip of a pencil on one picture.
In what looked like an open space among some trees was a tiny figure of a man. It seemed as if he were hacking at something with an ax. What the something was did not appear in the picture.
“I should say that it was half a mile, perhaps a mile, farther away than that grove,” commented Kennedy, making a rough calculation.
“On the old Davis farm,” considered MacLeod. “Look and see if you can’t make out the ruins of a house somewhere near-by. It was burned many years ago.”
“Yes, yes,” returned Kennedy, excitedly; “there’s the place! Do you think we can get there in a car before it’s dark?”
“Easily,” replied MacLeod.
It was only a matter of minutes before we three were poking about in a tangle of wood and field, seeking to locate the spot where Kennedy’s apparatus had photographed the lone axman.
At last, in a large, cleared field, we came upon a most peculiar heap of debris. As nearly as I could make out, it was a pile of junk, but most interesting junk. Practically all of it consisted in broken bits of the celluloid-like stuff we had seen in the abandoned building. Twisted inextricably about were steel wires and bits of all sorts of material. In the midst of the wreckage was something that looked for all the world like the remains of a gas-motor. It was not rusted, either, which indicated that it had been put there recently.
As he looked at it, Craig’s face displayed a smile of satisfaction.
“Looks as though it might have been an aeroplane of the tractor type,” he vouchsafed, finally.
“Surely there couldn’t have been an accident,” objected MacLeod. “No aviator could have lived through it, and there’s no body.”
“No; it was purposely destroyed,” continued Craig. “It was landed here from somewhere else for that purpose. That was what the man in the picture was doing with the ax. After the last explosion something happened. He brought the machine here to destroy the evidence.”
“But,” persisted MacLeod, “if there had been an aeroplane hovering about we should have seen it in the air, passing over the works at the time of the explosion.”
Kennedy picked the pieces, significantly.
“Some one about here has kept abreast of the times, if not ahead. See; the planes were of this non-inflammable celluloid that made it virtually transparent and visible only at a few hundred feet in the air. The aviator could fly low and so drop those pastilles accurately—and unseen. The engine had one of those new muffler-boxes. He would have been unheard, too, except for that delicate air-ship detector.”
MacLeod and I could but stare at each other, aghast. Without a doubt it was in the old merry-go-round building that the phantom aviator had established his hangar. What the connection was between the tragedy in the Snedden family and the tragedy in the powder-works we did not know, but, at least, now we knew that there was some connection.
It was growing dark rapidly, and, with some difficulty, we retraced our steps to the point where we had left the car. We whirled back to the town, and, of course, to the Snedden house.
Snedden was sitting in the parlor when we arrived, by the body of his wife, staring, speechless, straight before him, while several neighbors were gathered about, trying to console him. We had scarcely entered when a messenger-boy came up the path from the gate. Both Kennedy and MacLeod turned toward him, expecting some reply to the numerous messages of alarm sent out earlier in the afternoon.
“Telegram for Mrs. Snedden,” announced the boy.
“MRS. Snedden?” queried Kennedy, surprised, then quickly: “Oh yes, that’s all right. I’ll take care of it.”
He signed for the message, tore it open, and read it. For a moment his face, which had been clouded, smoothed out, and he took a couple of turns up and down the hall, as though undecided. Finally he crumpled the telegram abstractedly and shoved it into his pocket. We followed him as he went into the parlor and stood for several moments, looking fixedly on the strangely flushed face of Mrs. Snedden. “MacLeod,” he said, finally, turning gravely toward us, and, for the present, seeming to ignore the presence of the others, “this amazing series of crimes has brought home to me forcibly the alarming possibilities of applying modern scientific devices to criminal uses. New modes and processes seem to bring new menaces.”
“Like carbon-monoxide poisoning?” suggested MacLeod. “Of course it has long been known as a harmful gas, but—”
“Let us see,” interrupted Kennedy. “Walter, you were there when I examined Jackson’s car. There was not a drop of gasolene in the tank, you will recall. Even the water in the radiator was low. I lifted the hood. Some one must have tampered with the carburetor. It was adjusted so that the amount of air in the mixture was reduced. More than that, I don’t know whether you noticed it or not, but the spark and gas were set so that, when I did put gasolene in the tank, I had but to turn the engine over and it went. In other words, that car had been standing there, the engine running, until it simply stopped for want of fuel.” He paused while we listened intently, then resumed. “The gas-engine and gas-motor have brought with them another of those unanticipated menaces of which I spoke. Whenever