"Thank you," returned the detective. "You won't regret it. I can't tell you how much relieved I feel to have some one else, and, above all, yourself, on the case. You can get a train in half an hour. I think it would be best for you to go as though you had no connection with me--at least for the present."

Kennedy agreed, and MacLeod excused himself, promising to be on the train, although not to ride with us, in case we should be the target of too inquisitive eyes.

For a few moments, while our taxicab was coming, Kennedy considered thoughtfully what the company detective had said. By the time the vehicle arrived he had hurriedly packed up some apparatus in two large grips, one of which it fell to my lot to carry.

The trip down to Nitropolis was uninteresting, and we arrived at the little station shortly after noon. MacLeod was on the train, but did not speak to us, and it was perhaps just as well, for the cabmen and others hanging about the station were keenly watching new arrivals, and any one with MacLeod must have attracted attention. We selected or were, rather, selected by one of the cabmen and driven immediately to the Snedden house. Our cover was, as Craig and I had decided, to pose as two newspaper men from New York, that being the easiest way to account for any undue interest we might show in things.

The powder-company's plant was situated on a large tract of land which was surrounded by a barbed-wire fence, six feet high and constructed in a manner very similar to the fences used in protecting prison-camps in war-times. At various places along the several miles of fence gates were placed, with armed guards. Many other features were suggestive of war-times. One that impressed us most was that each workman had to carry a pa.s.s similar, almost, to a pa.s.sport. This entire fence, we learned, was patrolled day and night by armed guards.

A mile or so from the plant, or just outside the main gate, quite a settlement had grown up, like a mushroom, almost overnight--the product of a flood of new money. Originally, there had been only one house for some distance about--that of the Sneddens. But now there were scores of houses, mostly those of officials and managers, some of them really pretentious affairs. MacLeod himself lived in one of them, and we could see him ahead of us, being driven home.

The workmen lived farther along the line, in a sort of company town, which at present greatly resembled a Western mining-camp, though ultimately it was to be a bungalow town.

Just at present, however, it was the Snedden house that interested us most, for we felt the need of getting ourselves established in this strange community. It was an old-fashioned farm-house and had been purchased very cheaply by Snedden several years before. He had altered it and brought it up to date, and the combination of old and new proved to be typical of the owner as well as of the house.

Kennedy carried off well the critical situation of our introduction, and we found ourselves welcomed rather than scrutinized as intruders.

Garfield Snedden was much older than his second wife, Ida. In fact, she did not seem to be much older than Snedden's daughter Gertrude, whom MacLeod had already mentioned--a dashing young lady, never intended by nature to vegetate in the rural seclusion that her father had sought before the advent of the powder-works. Mrs. Snedden was one of those capable women who can manage a man without his knowing it. Indeed, one felt that Snedden, who was somewhat of both student and dreamer, needed a manager.

"I'm glad your train was on time," bustled Mrs. Snedden. "Luncheon will be ready in a few moments now."

We had barely time to look about before Gertrude led us into the dining-room and introduced us to the other boarders.

Knowing human nature, Kennedy was careful to be struck with admiration and amazement at everything we had seen in our brief whirl through Nitropolis. It was not a difficult or entirely a.s.sumed feeling, either, when one realized that, only a few short months before, the region had been nothing better than an almost hopeless wilderness of scrub-pines.

We did not have to wait long before the subject uppermost in our minds was brought up--the explosions.

Among the boarders there were at least two who, from the start, promised to be interesting as well as important. One was a tall, slender chap named Garretson, whose connection with the company, I gathered from the conversation, took him often on important matters to New York. The other was an older man, Jackson, who seemed to be connected with the management of the works, a reticent fellow, more given to listening to others than to talking himself.

"Nothing has happened so far to-day, anyhow," remarked Garretson, tapping the back of his chair with his knuckle, as a token of respect for that evil spirit who seems to be exorcised by knocking wood.

"Oh," exclaimed Gertrude, with a little half-suppressed shudder, "I do hope those terrible explosions are at last over!"

"If I had my way," a.s.serted Garretson, savagely, "I'd put this town under martial law until they WERE over."

"It may come to that," put in Jackson, quietly.

"Quite in keeping with the present tendency of the age," agreed Snedden, in a tone of philosophical disagreement.

"I don't think it makes much difference how you accomplish the result, Garfield," chimed in his wife, "as long as you accomplish it, and it is one that should be accomplished."

Snedden retreated into the refuge of silence. Though this was only a bit of the conversation, we soon found out that he was an avowed pacifist. Garretson, on the other hand, was an ardent militarist, a good deal of a fire-eater. I wondered whether there might not be a good deal of the poseur about him, too.

It needed no second sight to discover that both he and Gertrude were deeply interested in each other. Garretson was what Broadway would call "a live one," and, though there is nothing essentially wrong in that, I fancied that I detected, now and then, an almost maternal solicitude on the part of her stepmother, who seemed to be watching both the young man and her husband alternately. Once Jackson and Mrs. Snedden exchanged glances. There seemed to be some understanding between them.

The time to return to the works was approaching, and we all rose.

Somehow, Gertrude and Garretson seemed naturally to gravitate toward the door together.

Some distance from the house there was a large barn. Part of it had been turned into a garage, where Garretson kept a fast car. Jackson, also, had a roadster. In fact, in this new community, with its superabundant new wealth, everybody had a car.

Kennedy and I sauntered out after the rest. As we turned an angle of the house we came suddenly upon Garretson in his racer, talking to Gertrude. The crunch of the gravel under our feet warned them before we saw them, but not before we could catch a glimpse of a warning finger on the rosy lips of Gertrude. As she saw us she blushed ever so slightly.

"You'll be late!" she cried, hastily. "Mr. Jackson has been gone five minutes."

"On foot," returned Garretson, nonchalantly. "I'll overtake him in thirty seconds." Nevertheless, he did not wait longer, but swung up the road at a pace which was the admiration of all speed-loving Nitropolitans.

Craig had ordered our taxicab driver to stop for us after lunch, and, without exciting suspicion, managed to stow away the larger part of the contents of our grips in his car.

Still without openly showing our connection with MacLeod, Kennedy sought out the manager of the works, and, though scores of correspondents and reporters from various newspapers had vainly applied for permission to inspect the plant, somehow we seemed to receive the freedom of the place and without exciting suspicion. Craig's first move was to look the plant over. As we approached it our attention was instantly attracted to the numerous one-story galvanized-iron buildings that appeared to stretch endlessly in every direction. They seemed to be of a temporary nature, though the power-plants, offices, and other necessary buildings were very substantially built. The framework of the factory-buildings was nothing but wood, covered by iron sheathing, and even the sides seemed to be removable. The floors, however, were of concrete.

"They serve their purpose well," observed Kennedy, as we picked our way about. "Explosions at powder-mills are frequent, anyhow. After an explosion there is very little debris to clear away, as you may imagine. These buildings are easily repaired or replaced, and they keep a large force of men for these purposes, as well as materials for any emergency."

One felt instinctively the hazard of the employment. Everywhere were signs telling what not and what to do. One that stuck in my mind was, "It is better to be careful than sorry." Throughout the plant at frequent intervals were first-aid stations with kits for all sorts of accidents, including respirators, for workmen were often overcome by ether or alcohol fumes. Everything was done to minimize the hazard, yet one could not escape the conviction that human life and limb were as much a cost of production in this industry as fuel and raw material.

Once, in our wanderings about the plant, I recall we ran across both Garretson and Jackson in one of the offices. They did not see us, but seemed to be talking very earnestly about something. What it was we could not guess, but this time it seemed to be Jackson who was doing most of the talking. Kennedy watched them as they parted.

"There's something peculiar under the surface with those people at the boarding-house," was all he observed. "Come; over there, about an eighth of a mile, I think I see evidences of the latest of the explosions. Let's look at it."

MacLeod had evidently reasoned that, sooner of later, Kennedy would appear in this part of the grounds, and as we pa.s.sed one of the shops he joined us.

"You mentioned something about rumors of poisonous gases," hinted Craig, as we walked along.

"Yes," a.s.sented MacLeod; "I don't know what there is in it. I suppose you know that there is a very poisonous gas, carbon monoxide, or carbonic oxide, formed in considerable quant.i.ty by the explosion of several of the powders commonly used in sh.e.l.ls. The gas has the curious power of combining with the blood and refusing to let go, thus keeping out the oxygen necessary for life. It may be that that is what accounts for what we've seen--that it is actual poisoning to death of men not killed by the immediate explosion."

We had reached the scene of the previous day's disaster. No effort had yet been made to clear it up. Kennedy went over it carefully. What it was he found I do not know, but he had not spent much time before he turned to me.

"Walter," he directed, "I wish you would go back to the office near the gate, where I left that paraphernalia we brought down. Carry it over--let me see--there's an open s.p.a.ce there on that knoll. I'll join you there."

Whatever was in the packages was both bulky and heavy, and I was glad to reach the hillside he had indicated.

Craig was waiting for me there with MacLeod, and at once opened the packages. From them he took a thin steel rod, which he set up in the center of the open s.p.a.ce. To it he attached a frame and to the frame what looked like four reversed megaphones. Attached to the frame, which was tubular, was an oak box with a little arrangement of hard rubber and metal which fitted into the ears. For some time Kennedy's face wore a set, far-away expression, as if he were studying something.

"The explosions seem always to occur in the middle of the afternoon,"

observed MacLeod, fidgeting apprehensively.

Kennedy motioned petulantly for silence. Then suddenly he pulled the tubes out of his ears and gazed about sharply.

"There's something in the air!" he cried. "I can hear it!"

MacLeod and I strained our eyes. There was nothing visible.

"This is an anti-aircraft listening-post, such as the French use,"

explained Craig, hurriedly. "Between the horns and the microphone in the box you can catch the hum of an engine, even when it is m.u.f.fled. If there's an aeroplane or a Zeppelin about, this thing would locate it."

Still, there was nothing that we could see, though now the sound was just perceptible to the ear if one strained his attention a bit. I listened. It was plain in the detector; yet nothing was visible. What strange power could it be that we could not see or feel in broad daylight?

Just then came a low rumbling, and then a terrific roar from the direction of the plant. We swung about in time to see a huge cloud of debris lifted literally into the air above the tree-tops and dropped to earth again. The silence that succeeded the explosion was eloquent. The phantom destroyer had delivered his blow again.

"The distillery--where we make the denatured alcohol!" cried MacLeod, gazing with tense face as from other buildings, we could see men pouring forth, panic-stricken, and the silence was punctured by shouts.