Early that afternoon, accordingly, we found ourselves at the door of the large stone house on Riverside Drive in which Mrs. Rogers lived.  Kennedy inquired for her, and we were admitted to a large reception-room, the very decorations of which showed evidence of her leaning toward the Orient.  Mrs. Rogers proved to be a widow of baffling age, good-looking, with a certain indefinable attractiveness.

Kennedy’s cue was obvious.  It was to be an eager neophyte in the mysteries of the East, and he played the part perfectly without overdoing it.

“Perhaps you would like to come to some of the meetings of our Cult of the Occult,” she suggested.

“Delighted, I am sure,” returned Kennedy.  She handed him a card.

“We have a meeting this afternoon at four,” she explained.  “I should be glad to welcome you among us.”

Kennedy thanked her and rose to go, preferring to say nothing more just then about the problems which vexed us in the Shirley case, lest it should make further investigation more difficult.

Nothing more had happened at the hotel, as we heard from Grady a few minutes later, and, as there was some time before the cult met, we returned to the laboratory.

Things had evidently progressed well, even in the few hours that he had been studying his meager evidence.  Not only was he making a series of delicate chemical tests, but, in cases, he had several guinea-pigs which he was using also.

He now studied through a microscope some of the particles of dust from the vacuum cleaner.

“Little bits of glass,” he said, briefly, taking his eye from the eyepiece.  “Captain Shirley was not shot.”

“Not shot?” I repeated.  “Then how was he killed?”

Kennedy eyed me gravely.

“Shirley was murdered by a poisoned bomb!”

I said nothing, for the revelation was even more startling than I had imagined.

“In that package which was placed in his room,” he went on, “must have been a little infernal machine of glass, constructed so as to explode the moment the wrapper was broken.  The flying pieces of glass injected the poison as by a myriad of hypodermic needles—­ the highly poisonous toxin of abrin, product of the jequirity, which is ordinarily destroyed in the stomach but acts powerfully if injected into the blood.  Shirley died of jequirity poisoning, or rather of the alkaloid in the bean.  It has been used in India for criminal poisoning for ages.  Only, there it is crushed, worked into a paste, and rolled into needle-pointed forms which prick the skin.  Abrin is composed of two albuminous bodies, one of which resembles snake-venom in all its effects, attacking the heart, making the temperature fall rapidly, and leaving the blood fluid after death.  It is a vegetable toxin, quite comparable with ricin from the castor-oil bean.”

In spite of my horror at the diabolical plot that had been aimed at Shirley, my mind ran along, keenly endeavoring to piece together the scattered fragments of the case.  Some one, of course, had sent the package while he was out and had it placed in his room.  Had it been the same person who had sent the single jequirity bean?  My mind instantly reverted to the strange woman across the hall, the photograph in his luggage, and the broken necklace in the jewel-case.