"Better let Boyd see them when he comes down. The affair grows more queer and complicated as we proceed." "Don't you recollect," I said suddenly, "in the dead man's pocket was a card exactly similar, but quite blank. You threw it into the fireplace." "Ah! of course," he answered quickly. "That fact shows that he had something to do with these mysterious symbols. I wonder what is their real meaning." "I wonder," I said. "As you say, the mystery grows each moment more and more inexplicable. Curious, too, that the snake in the garden path should have directed your attention to it." "No," he said quickly, his face in an instant pale and serious, "don't mention that, there's a good fellow. I'm trying not to think of it; for when I recollect all that it means to me I'm unnerved." "Bah!" I laughed. "Surely there's nothing to fear. It only shows that however careful the assassin is to cover his crime it must be unearthed sooner or later. The finger of Fate always points to the crime of murder, however well it may be concealed." "True," he sighed, his brows knit in serious thought. "But the finger of Fate has in this case shown me an omen of evil." "You're a fool, Patterson," I said bluntly. "You have here every chance to distinguish yourself as a shrewd officer, yet you calmly stand by talking of omens and all that rot." "Yes," he answered. "I know I'm an idiot, Mr. Urwin, but I can't help it. That's the worst of it." "Well," I suggested, "while Boyd is upstairs, why not make inquiries of the next-door neighbours regarding those who occupied this place?" He at once acted on my suggestion, and together we went out and rang the bell of the house adjoining on the right. My friend's curious apathy in this matter surprised me, for usually he was a quick, active fellow, who prosecuted his inquiries methodically, and worked up evidence in a manner that had more than once called forth the commendation of the judge at the Old Bailey. That night, however, he was plainly upset-- nervous, trembling and agitated, in a manner quite unusual to him. Boyd, the keen-eyed, quick-witted detective inspector, had noticed this when at the police-station, but Patterson had only replied-- "I'm a bit unwell, that's all." Our summons at the house next door was answered by the occupier's wife, a rather stout, white-haired, gaily-capped old lady named Luff. The appearance of Patterson in uniform surprised her, but when she had asked us in, and we were seated, he said-- "There is no occasion to be alarmed, madam. I have merely called to make an inquiry of you. It is in your power to render us assistance in a rather confidential matter regarding the occupiers of the house next door--your neighbours on the left. What do you know of them?"