"No, Holford," went on my mysterious neighbour, very seriously, "you are like most other men--far too inquisitive. Had you been able to repress your curiosity, and at the same time preserve your pledge of secrecy, matters to-day would have been vastly different, and, acting in concert, we might have been able to solve this extraordinary enigma of Professor Greer's death. But now you've been and made all sorts of wild statements to the Commissioner of Police. Well, it has stultified all my efforts." He spoke with such an air of injured innocence that I hesitated whether I had not, after all, somewhat misjudged him. Yet as I looked into that grey, crafty face I could not help doubting him. It was true that he had taken me into his confidence, but was it not done only for his own ingenious and devilish purpose? "My wife is lost," I observed at last. "It is her loss that has, perhaps, led me to say more than I would otherwise have done." "And love for your wife makes you forget your word of honour given to me, eh?" he asked. "Your code of honour is distinctly peculiar, Mr. Holford," he added, with biting sarcasm. "I, of course, regret that Mrs. Holford has fallen a victim to the machinations of our enemies, but surely even that is no excuse for a man to act treacherously towards his friend." "That is not the point," I declared. "You have never satisfied me as to your motive in taking me to Sussex Place and exhibiting to me the evidence of the crime." "Because--well, because, had I done so, you would not have understood. Some day, perhaps, you will know; and when you learn the truth you will be even more astounded than you are to-day. Meanwhile, I can assure you that you suspect me entirely without cause." "Then why were you in the house at the time the traces of the crime were being effaced in the furnace?" I asked in a hard voice. He hesitated for a moment, and I thought his bony hand trembled slightly. "For reason's of my own," he replied at last. "You allowed me to wriggle out of a very tight corner, and I intended to show you my gratitude, had you given me an opportunity." "I desire no expression of gratitude, Mr. Kirk," I replied, with dignified disgust. "All I require is a statement from you concerning the whereabouts of my dear wife. Give me that, and I'm satisfied to retire from the whole affair altogether." "Because you have now realised that Scotland Yard refuse their assistance, eh?" he asked, with an evil grin. "Are you not now agreed with me that our much-praised Criminal Investigation Department, with all its hide-bound rules and its tangle of red tape, is useless? It is not the men who are at fault--for some of them are the finest and best fellows in the whole metropolis--but the system which is radically wrong." I was bound, after my experience, to agree with him. But again I referred to Mabel, and to the manner in which she had been decoyed from home.