"Naturally. But I hope you will soon learn to trust me," was his quiet retort. "I called you back to-night in order to see if you--my most intimate friend--would recognise me. But you do not. I am, therefore, safe--safe to go forth and perform a certain mission which it is imperative that I should perform." "You are fooling me," I declared. For a second he looked straight and unflinchingly into my eyes, then with a sudden movement he drew the left cuff of his dress shirt up to the elbow and held out his forearm for me to gaze upon. I looked. Then I stood dumbfounded, for half-way up the forearm, on the inside, was the cicatrice of an old knife wound which long ago, he had told me, had been made by an Indian in South America who had attempted to kill him, and whom he had shot in self-defence. "You believe me now?" he asked, in a voice scarce above a whisper. "Of course," I said. "Pardon me, Digby--but this change in your personality is marvellous--almost superhuman!" "So I've been told before," he replied lightly. "But, really, didn't you penetrate it?" he asked, resuming his normal voice. "No. I certainly did not," I answered, and helping myself to a drink, swallowed it. "Well?" I went on. "What does this mean?" "At present I can't exactly tell you what I intend doing," he replied. "To-night I wanted to test you, and have done so. It's late now," he added, glancing at the clock, which showed it to be half-past two o'clock in the morning. "Come in to-morrow at ten, will you?" he asked. "I want to discuss the future with you very seriously. I have something to say which concerns your own future, and which also closely concerns a friend of yours. So come in your own interests, Royle--now don't fail, I beg of you!" "But can't you tell me to-night," I asked. "Not until I know something of what my own movements are to be," he replied. "I cannot know before to-morrow," he replied with a mysterious air. "So if you wish to be forewarned of an impending peril, come and see me and I will then explain. We shall, no doubt, be on closer terms to-morrow. _Au revoir_," and he took my hand warmly and then let me out. The rather narrow, ill-lit staircase, the outer door of which had been shut for hours, was close and stuffy, but as I descended the second flight and was about to pass along the hall to the door, I distinctly heard a movement in the shadow where, on my left, the hall continued along to the door of the ground-floor flat. I peered over the banisters, but in the darkness could distinguish nothing. That somebody was lurking there I instantly felt assured, and next moment the truth became revealed by two facts. The first was a light, almost imperceptible noise, the jingle of a woman's bangles, and, secondly, the faint odour of some subtle perfume, a sweet, intoxicating scent such as my nostrils had never greeted before.