"You being the clever man who understands, etcetera," I said, as seriously as I could, "and I the censorious and cruel old maid who is invariably a fool." "You put it crudely," he rejoined complacently, "and had you not given ample proof of your intelligence before now I might have thought it worth while to refute the second half of your argument. As for the first..." "Hadn't you better tell me about the Fulton Gardens Mystery?" I broke in impatiently. "Certainly," he replied, in no way abashed. "I have meant to talk to you about it all along, only that you would digress." "_Pax!_" I retorted, and with a conciliatory smile I handed him a beautiful bit of string. He pounced on it with thin hands that looked like the talons of a bird, and he gloated on that bit of string for all the world as on a prey. "I dare say," he began, "that to most people the mystery appeared baffling enough. But to me ... Well, there was the victim of what you very properly call the cowardly assault, your friend--or acquaintance--Mr. Seton Jessup, a man on the wrong side of sixty, but very active and vigorous for his years. He carried on the business of pearl merchant in Fulton Gardens, but he did not live there, as you know. He was a married man, had sons and daughters and a nice house in Fitzjohn's Avenue. He also owned the house in Fulton Gardens, a four-storied building of the pattern prevalent in that neighbourhood. The ground floor, together with the one above that, and the basement were used by Mr. Jessup himself for his business: on the ground floor he had his office and showroom, above that were a couple of reception rooms, where he usually had his lunch and saw a few privileged customers, and in the basement there was a kitchen with scullery and pantry, a small servants' hall, and a strong-room for valuables. The top story of all was let to a surgical-instrument maker who did not sleep on the premises, and the second floor--that is the one just below the surgical-instrument maker and immediately above the reception rooms--was occupied by Mrs. Tufnell, who was cook-housekeeper to Mr. Jessup, and her niece, Ann Weber, who acted as the house-parlourmaid. Mrs. Tufnell's son, Mark, who was a junior clerk in the office, did not sleep in the house. He was considered to be rather delicate, and lived with a family somewhere near the Alexandra Palace.