Craig laid down on the table the reed stick with the little darkened cylinder on the end.
"That," he said, "is a little article which I picked up beneath Northrop's window yesterday. It is a piece of anno-noki, or bushi." I fancied I saw just a glint of satisfaction in Otaka's eyes.
"Like many barbarians," continued Craig, "the Ainus from time immemorial have prepared virulent poisons with which they charged their weapons of the chase and warfare. The formulas for the preparations, as in the case of other arrow poisons of other tribes, are known only to certain members, and the secret is passed down from generation to generation as an heirloom, as it were. But in this case it is no longer a secret. It has now been proved that the active principle of this poison is aconite."
"If that is the case," broke in Doctor Leslie, "it is hopeless to connect anyone directly in that way with these murders. There is no test for aconitin."
I thought Sato's face was more composed and impassive than ever. Doctor Bernardo, however, was plainly excited.
"What--no test--NONE?" asked Kennedy, leaning forward eagerly. Then, as if he could restrain the answer to his own question no longer, he shot out: "How about the new starch test just discovered by Professor Reichert, of the University of Pennsylvania? Doubtless you never dreamed that starch may be a means of detecting the nature of a poison in obscure cases in criminology, especially in cases where the quantity of poison necessary to cause death is so minute that no trace of it can be found in the blood.
"The starch method is a new and extremely inviting subject to me. The peculiarities of the starch of any plant are quite as distinctive of the plant as are those of the hemoglobin crystals in the blood of an animal. I have analyzed the evidence of my microscope in this case thoroughly. When the arrow poison is introduced subcutaneously--say, by a person shooting a poisoned dart, which he afterward removes in order to destroy the evidence- -the lethal constituents are rapidly absorbed.
"But the starch remains in the wound. It can be recovered and studied microscopically and can be definitely recognized. Doctor Reichert has published a study of twelve hundred such starches from all sorts of plants. In this case, it not only proves to be aconitin but the starch granules themselves can be recognized. They came from this piece of arrow poison."
Every eye was fixed on him now.
"Besides," he rapped out, "in the soft soil beneath the window of Professor Northrop's room, I found footprints. I have only to compare the impressions I took there and those of the people in this room, to prove that, while the real murderer stood guard below the window, he sent some one more nimble up the rain pipe to shoot the poisoned dart at Professor Northrop, and, later, to let down a rope by which he, the instigator, could gain the room, remove the dart, and obtain the key to the treasure he sought."
Kennedy was looking straight at Professor Bernardo.
"A friend of mine in Mexico has written me about an inscription," he burst out. "I received the letter only to-day. As nearly as I can gather, there was an impression that some of Northrop's stuff would be valuable in proving the alleged kinship between Mexico and Japan, perhaps to arouse hatred of the United States."
"Yes--that is all very well," insisted Kennedy. "But how about the treasure?"
"Treasure?" repeated Bernardo, looking from one of us to another.
"Yes," pursued Craig relentlessly, "the treasure. You are an expert in reading the hieroglyphics. By your own statement, you and Northrop had been going over the stuff he had sent up. You know it."
Bernardo gave a quick glance from Kennedy to me. Evidently he saw that the secret was out.
"Yes," he said huskily, in a low tone, "Northrop and I were to follow the directions after we had plotted them out and were to share it together on the next expedition, which I could direct as a Mexican without so much suspicion. I should still have shared it with his widow if this unfortunate affair had not exposed the secret."
Bernardo had risen earnestly.
"Kennedy," he cried, "before God, if you will get back that stone and keep the secret from going further than this room, I will prove what I have said by dividing the Mixtec treasure with Mrs. Northrop and making her one of the richest widows in the country!"
"That is what I wanted to be sure of," nodded Craig. "Bernardo, Senora Herreria, of whom your friend wrote to you from Mexico, has been murdered in the same way that Professor Northrop was. Otaka was sent by her husband to murder Northrop, in order that they might obtain the so-called 'Pillar of Death' and the key to the treasure. Then, when the senora was no doubt under the influence of sake in the pretty little Oriental bower at the curio shop, a quick jab, and Otaka had removed one who shared the secret with them."
He had turned and faced the pair.
"Sato," he added, "you played on the patriotism of the senora until you wormed from her the treasure secret. Evidently rumors of it had spread from Mexican Indians to Japanese visitors. And then, Otaka, all jealousy over one whom she, no doubt, justly considered a rival, completed your work by sending her forth to die, unknown, on the street. Walter, ring up First Deputy O'Connor. The stone is hidden somewhere in the curio shop. We can find it without Sato's help. The quicker such a criminal is lodged safely in jail, the better for humanity."
Sato was on his feet, advancing cautiously toward Craig. I knew the dangers, now, of anno-noki, as well as the wonders of jujutsu, and, with a leap, I bounded past Bernardo and between Sato and Kennedy.
How it happened, I don't know, but, an instant later, I was sprawling.
Before I could recover myself, before even Craig had a chance to pull the hair-trigger of his automatic, Sato had seized the Ainu arrow poison from the table, had bitten the little cylinder in half, and had crammed the other half into the mouth of Otaka.
Chapter XIII
The Radium Robber
Kennedy simply reached for the telephone and called an ambulance. But it was purely perfunctory. Dr. Leslie himself was the only official who could handle Sato's case now.
We had planned a little vacation for ourselves, but the planning came to naught. The next night we spent on a sleeper. That in itself is work to me.
It all came about through a hurried message from Murray Denison, president of the Federal Radium Corporation. Nothing would do but that he should take both Kennedy and myself with him post-haste to Pittsburgh at the first news of what had immediately been called "the great radium robbery."
Of course the newspapers were full of it. The very novelty of an ultra-modern cracksman going off with something worth upward of a couple of hundred thousand dollars--and all contained in a few platinum tubes which could be tucked away in a vest pocket--had something about it powerfully appealing to the imagination.
"Most ingenious, but, you see, the trouble with that safe is that it was built to keep radium IN--not cracksmen OUT," remarked Kennedy, when Denison had rushed us from the train to take a look at the little safe in the works of the Corporation.
"Breaking into such a safe as this," added Kennedy, after a cursory examination, "is simple enough, after all."
It was, however, a remarkably ingenious contrivance, about three feet in height and of a weight of perhaps a ton and a half, and all to house something weighing only a few grains.
"But," Denison hastened to explain, "we had to protect the radium not only against burglars, but, so to speak, against itself. Radium emanations pass through steel and experiments have shown that the best metal to contain them is lead. So, the difficulty was solved by making a steel outer case enclosing an inside leaden shell three inches thick."
Kennedy had been toying thoughtfully with the door.
"Then the door, too, had to be contrived so as to prevent any escape of the