There was as yet no hint of answer, and our only plan was to watch again that night. This time O'Connor, not knowing where the lightning would strike next, took Craig's suggestion and we determined to spend the time cruising about in the fastest of the police motor boats, while the force of watchers along the entire shore front of the city was quietly augmented and ordered to be extra vigilant.
O'Connor at the last moment had to withdraw and let us go alone, for the worst, and not the unexpected, happened in his effort to clean up Chinatown. The war between the old rivals, the Hep Sing Tong and the On Leong Tong, those ancient societies of troublemakers in the little district, had broken out afresh during the day and three Orientals had been killed already.
It is not a particularly pleasant occupation cruising aimlessly up and down the harbour in a fifty-foot police boat, staunch and fast as she may be.
Every hour we called at a police post to report and to keep in touch with anything that might interest us. It came at about two o'clock in the morning and of all places, near the Battery itself. From the front of a ferry boat that ran far down on the Brooklyn side, what looked like two flashlights gleamed out over the water once, then twice.
"Headlights of an automobile," remarked Craig, scarcely taking more notice of it, for they might have simply been turned up and down twice by a late returning traveller to test them. We were ourselves near the Brooklyn shore. Imagine our surprise to see an answering light from a small boat in the river which was otherwise lightless. We promptly put out our own lights and with every cylinder working made for the spot where the light had flashed up on the river. There was something there all right and we went for it.
On we raced after the strange craft, the phantom that had scared Staten Island. For a mile or so we seemed to be gaining, but one of our cylinders began to miss—the boat turned sharply around a bend in the shore. We had to give it up as well as trying to overtake the ferry boat going in the opposite direction.
Kennedy's equanimity in our apparent defeat surprised me. "Oh, it's nothing, Walter," he said. "They slipped away to-night, but I have found the clue. To-morrow as soon as the Customs House is open you will understand. It all centres about opium."
At least a large part of the secret was cleared, too, as a result of Kennedy's visit to the Customs House. After years of fighting with the opium ring on the Pacific coast, the ring had tried to "put one over" on the revenue officers and smuggle the drug in through New York.
It did not take long to find the right man among the revenue officers to talk with. Nor was Kennedy surprised to learn that Nichi Moto had been in fact a Japanese detective, a sort of stool pigeon in Clendenin's establishment working to keep the government in touch with the latest scheme.
The finding of the can of opium on the scene of the murder of Bertha Curtis, and the chase after the lightless motor boat had at last placed Kennedy on the right track. With one of the revenue officers we made a quick trip to Brooklyn and spent the morning inspecting the ships from South American ports docked in the neighbourhood where the phantom boat had disappeared.
From ship to ship we journeyed until at last we came to one on which, down in the chain locker, we found a false floor with a locker under that. There was a compartment six feet square and in it lay, neatly packed, fourteen large hermetically sealed cylinders, each full of the little oblong tins such as Kennedy had picked up the other day—forty thousand dollars' worth of the stuff at one haul, to say nothing of the thousands that had already been landed at one place or another.
It had been a good day's work, but as yet it had not caught the slayer or cleared up the mystery of Bertha Curtis. Some one or something had had a power over the girl to lure her on. Was it Clendenin? The place in Forty-fourth Street, on inquiry, proved to be really closed as tight as a drum. Where was he?
All the deaths had been mysterious, were still mysterious. Bertha Curtis had carried her secret with her to the grave to which she had been borne, willingly it seemed, in the red car with the unknown companion and the goggled chauffeur. I found myself still asking what possible connection she could have with smuggling opium.
Kennedy, however, was indulging in no such speculations. It was enough for him that the scene had suddenly shifted and in a most unexpected manner. I found him voraciously reading practically everything that was being printed in the papers about the revival of the tong war.
"They say much about the war, but little about the cause," was his dry comment. "I wish I could make up my mind whether it is due to the closing of the joints by O'Connor, or the belief that one tong is informing on the other about opium smuggling."
Kennedy passed over all the picturesque features in the newspapers, and from it all picked out the one point that was most important for the case which he was working to clear up. One tong used revolvers of a certain make; the other of a different make. The bullet which had killed Bertha Curtis and later Nichi Moto was from a pistol like that of the Hep Sings.
The difference in the makes of guns seemed at once to suggest something to Kennedy and instead of mixing actively in the war of the highbinders he retired to his unfailing laboratory, leaving me to pass the time gathering such information as I could. Once I dropped in on him but found him unsociably surrounded by microscopes and a very sensitive arrangement for taking microphotographs. Some of his negatives were nearly a foot in diameter, and might have been, for all I knew, pictures of the surface of the moon.
While I was there O'Connor came in. Craig questioned him about the war of the tongs.
"Why," O'Connor cried, almost bubbling over with satisfaction, "this afternoon I was waited on by Chin Jung, you remember?—one of the leading merchants down there. Of course you know that Chinatown doesn't believe in hurting business and it seems that he and some of the others like him are afraid that if the tong war is not hushed up pretty soon it will cost a lot in money. They are going to have an anniversary of the founding of the Chinese republic soon and of the Chinese New Year and they are afraid that if the war doesn't stop they'll be ruined."
"Which tong does he belong to?" asked Kennedy, still scrutinising a photograph through his lens.
"Neither," replied O'Connor. "With his aid and that of a Judge of one of our courts who knows the Chinaman like a book we have had a conference this afternoon between the two tongs and the truce is restored again for two weeks."
"Very good," answered Kennedy, "but it doesn't catch the murderer of Bertha Curtis and the Jap. Where is Clendenin, do you suppose?"
"I don't know, but it at least leaves me free to carry on that case. What are all these pictures?"
"Well," began Kennedy, taking his glass from his eye and wiping it carefully, "a Paris crime specialist has formulated a system for identifying revolver bullets which is very like that of Dr. Bertillon for identifying human beings."
He picked up a handful of the greatly enlarged photographs. "These are photographs of bullets which he has sent me. The barrel of every gun leaves marks on the bullet that are always the same for the same barrel but never identical for two different barrels. In these big negatives every detail appears very distinctly and it can be decided with absolute certainty whether a given bullet was fired from a given revolver. Now, using this same method, I have made similar greatly enlarged photographs of the two bullets that have figured so far in this case. The bullet that killed Miss Curtis shows the same marks as that which killed Nichi."
He picked up another bunch of prints. "Now," he continued, "taking up the firing pin of a rifle or the hammer of a revolver, you may not know it but they are different in every case. Even among the same makes they are different, and can be detected.
"The cartridge in either a gun or revolver is struck at a point which is never in the exact centre or edge, as the case may be, but is always the same for the same weapon. Now the end of the hammer when examined with the microscope bears certain irregularities of marking different from those of every other gun and the shell fired in it is impressed with the particular markings of that hammer, just as paper