"She must have crossed the street to get to that side." "Yes, sir; she did. I noticed pertic'lar, for I thought it funny she shouldn't 've let me drive her on down th' street to wherever she was goin'. It's a dirty place along there, sir." "Yes, I know. When you drove her out on the 28th--the day she brought back the maid--where did she go?" "To Washington Square again, sir." "And left you waiting for her?" "Yes, sir; just th' same." "And went down the same street?" "Yes, sir; crossed to th' east side just th' same as th' time before." "How long was she gone?" "Over an hour, sir; an hour an' a half, I should say." "Did you notice anything unusual in her appearance when she came back?" "No, sir; she was wearin' a heavy veil. She had th' other woman with her, an' she just said 'Home!' in a kind o' hoarse voice, as I helped them into th' carriage." That was all that he could tell me, and yet I felt that it would help me greatly. In the first place, it narrowed my investigations to the district lying to the east of West Broadway, and I knew that the French quarter extended only a block or two in that direction. And again, it gave me a point to insist on in my inquiries--I knew the date upon which the mysterious woman had left her lodging. Or, at least, I knew that it must be one of two dates. The lodging had been vacated, then, either on the twenty-eighth of March or the third of April. As a last resource, I had the photograph. I was ready to begin my search, and dismissed Brooks, warning him to say nothing to anyone about the mystery. As I passed out the door to the pavement, I happened to glance across the way, and there, in the crowd of brokers which always lines the street, I perceived Martigny. He was listening intently to one of the brokers, who was talking earnestly in his ear--telling him how to make his fortune, I suppose--and did not see me. For an instant, I was tempted to cross to him, and get him out of danger. Then I smiled at the absurdity of the thought. It would take a clever man to fleece Martigny, and I recalled his strong face, his masterful air--he was no fool, no lamb ready for the shears. He was perfectly able to look out for himself--to wield the shears with power and effect, if need be. I turned west toward Broadway, still, I suppose, thinking of him subconsciously: for a few moments later, some irresistible impulse caused me to glance around. And there he was, walking after me, on the opposite side of the street! Then, in a flash, I understood. He was following me!