“You must have thought me very rude to hurry away as I did, but I wanted to get home.”

There were many matters I wished she would explain, but how could I ask her point-blank? For what reason had she taken me to Blackheath that night on a fruitless errand, and what connexion had she with the mysterious Purvis?

Again, it occurred to me that if Reilly had watched that newsagent’s in Sterndale Road he had probably met her. He might even have become acquainted with her for aught I knew. I had, I remembered, given him a detailed description.

But if they were acquainted, she would be utterly unaware of the young man’s association with me; hence I dare not broach the subject.

While I lingered at her side I could not help remarking, within myself, upon her affable courtesy and modest reserve towards me. A mystery surrounded her; that was certain. But in that half-hour I spent with her in Westbourne Grove I felt that she was not an adventuress, as I had half believed her to be, and that, save for the fact that she scrupulously concealed her place of abode, she was open and honest-minded, with a pleasing grace and sweet smile.

Again, just as I had noticed on the first occasion we had met, I detected that concealed within her heart was some deep-rooted sorrow, some painful memory of the past, perhaps, that she could not forget, and that now and then the sympathetic chord was struck that brought it all back to her, causing that expression of sadness which appeared at intervals in her eyes, and those half-suppressed sighs which she believed I did not notice.

Near midday she took leave of me at Queen’s Road Station, for she would not allow me to remain with her longer.

“You are really mysterious, Miss Bristowe,” I laughed; “I’ve spent a most delightful hour, and am most unwilling to end our chat.”

“Ah,” she said, earnestly; “you must, doctor. You’ve been with me already too long. Among all these people passing there may be one who knows me, and has noticed me walking with a stranger.”

“Well, is it such a terrible sin?” I laughed.