taking it for granted that the lady in black had followed me from Kensington to this shop; that, in fact, she was none other than Mrs. Schallibaum. And, indeed, the circumstances had rendered the conclusion inevitable. In the very instant when I had perceived the displacement of the left eye, complete recognition had come upon me. When I had stood facing the woman, the brief glance at her face had conveyed to me something dimly reminiscent of which I had been but half conscious and had instantly forgotten. But the sight of that characteristic squint had at once revived and explained it. That the woman was Mrs. Schallibaum I now felt no doubt whatever.
Nevertheless, the whole affair was profoundly mysterious. As to the change in the woman's appearance, there was little in that. The coarse, black hair might be her own, dyed, or it might be a wig. The eyebrows were made-up; it was a simple enough proceeding and made still more simple by the beaded veil. But how did she come to be there at all? How did she happen to be made-up in this fashion at this particular time? And, above all, how came she to be provided with a lump of what I had little doubt was poisoned sugar?
I turned over the events of the day, and the more I considered them the less comprehensible they appeared. No one had followed the omnibus either on foot or in a vehicle, as far as I could see; and I had kept a careful look-out, not only at starting but for some considerable time after.