The hoarse voice ceased. Neither Gatton nor I moved or spoke. Then:  
"I have three minutes—or less," whispered Damar Greefe. "Question me. I am at your service."
 
"Where is your villa?" asked Gatton suddenly.
 
"It is called The Laurels—"
 
"The Laurels!" I cried incredulously.
 
"It is called so," whispered the Eurasian. "It is the last house but one in College Road! From there I conducted my last experiment with L.K. Vapor, which resulted not in the death of Mr. Addison, but in that of Eric Coverly—"
 
Gatton sprang to his feet.
 
"Come along, Mr. Addison!" he cried. But:
 
"The Laurels is empty," came, ever more faintly. "In her Sothic fury, Nahémah fled. The bloodlust is upon her. I warn you. She is more dangerous ... than ... any rabid dog.... Tuberculosis will end her life ... before the snows ... come. But there is time for her to ... Ah, God's mercy!"
 
He writhed. He was contorted. Foam appeared Upon his lips.
 
"Hlangkûna!" he moaned, "hlangkûna! She ... touched me with a poisoned needle ... two hours—ago...."
 
He rose to his full height, uttered a stifled scream, and crashed down upon the floor—dead!
 
In a species of consternation, Gatton and I stood looking at one another—standing rigidly like men of stone one on either side of that long, thin body stretched upon my study floor. The hawk face in profile was startlingly like that of Anubis as it lay against the red carpet.
 
Neither of us, I think, was capable of grasping the fact that the inquiry was all but ended and that the mysteries which had seemed so dark and insoluble were cleared up and the inner workings of this strange conspiracy laid bare before us. One thought, I believe, was uppermost in both our minds: that the man who now lay dead upon the floor, a victim of one of his own devilish inventions, was no more than a brilliant madman.
 
If his great work on the ape-men of Abyssinia and that greater one dealing with what he called "the psycho-hybrids" had ever had existence outside his own strange imagination no one was ever likely to know. But that Dr. Damar Greefe was a genius whom much learning had made mad, neither of us doubted.
 
The whole thing seemed the wildest phantasy, and, for a time, in doubting the reality of the Eurasian's work, I found myself doubting the evidence of my own senses and seriously wondering if this possessed witch-cat whose green eyes had moved like Satanic lanterns throughout the whole phantasmagoria, had any more palpable existence than the other strange things spoken of by the unscrupulous scientist.
 
That Gatton's thoughts had been running parallel with my own was presently made manifest, for:
 
"Without a moment's delay, Mr. Addison," he said, speaking like a man newly awakened from slumber, "we must proceed to The Laurels and test the truth of what we have heard."
 
He crossed to the door, threw it open, and:
 
"Sergeant!" he cried. "Come in! The prisoner is dead!"
 
As the sergeant and the constable who were waiting came into the study and stood looking in stupefaction at the body stretched on the floor, I heard the telephone bell ring. I started nervously. That sound awakened ghastly memories, and I thought of the man who only a few hours before had met his death in the room where now the bell was ringing its summons.
 
I doubted if I could ever spend another night beneath that roof, for here Dr. Damar Greefe, the arch-assassin, and one of his victims both had met their ends. I heard the voice of Coates speaking in the adjoining room, and presently, as Gatton went to the door:
 
"Miss Merlin wishes to speak to you, sir," said Coates.
 
I ran eagerly to the 'phone, and:
 
"Hello!" I cried. "Is that you, Isobel?"
 
"Yes!" came her reply, and I noted the agitation in her voice. "I am more dreadfully frightened than I have ever been in my life. If only you were here! Is it possible for you to come at once?"
 
"What has alarmed you?" I asked anxiously.
 
"I can't explain," she replied. "It is a dreadful sense of foreboding—and all the dogs in the neighborhood seem to have gone mad!"
 
"Dogs!" I cried, a numbing fear creeping over me. "You mean that they are howling?"
 
"Howling!" she answered. "I have never heard such a pandemonium at any time. In my present state of nerves, Jack, I did the wrong thing in coming to this funny lonely little house. I feel deserted and hopeless and, for some reason, in terrible danger."
 
"Are you alone, then?" I asked, in ever growing anxiety.
 
To my utter consternation:
 
"Yes!" she replied. "Aunt Alison was called away half an hour ago—to identify some one at a hospital who had asked for her—"
 
"What! an accident?"
 
"I suppose so."
 
"But the servants?"
 
"Cook left this morning. You remember Aunt told you she was leaving."
 
"There is the girl, Mary?"
 
"Aunt 'phoned for her to join her at the hospital!"
 
"What! I don't understand! 'Phoned, you say? Was it Mrs. Wentworth herself who 'phoned?"
 
"No; I think not. One of the nurses, Mary said. But at any rate, she has gone, Jack, and I'm frightened to death! There's something else," she added.
 
"Yes?" I said eagerly.
 
She laughed in a way that sounded almost hysterical.
 
"Since Mary went I have thought once or twice that I have seen some one or something creeping around outside the house in the shadows amongst the trees! And just a while ago something happened which really prompted me to 'phone you."
 
"What was it?"
 
"I heard a sort of scratching at an upper window. It was just like—"
 
"Yes! Yes!"
 
"Like a great cat trying to gain admittance!"
 
"See that all the doors and windows are fastened!" I cried. "Whatever happens or whoever knocks don't open to any one, you understand? We will be with yo............