“What kind of a person called?” I asked.

“A woman, sir; not a lady.  On foot—­poorly dressed.  She’s been here before, and Dr. Lowry has visited the case twice.  No. 19 Bellringer Street.  Perhaps you will find him in the case-book, sir.”

I went in to consult the case-book.  Half a dozen words contained the diagnosis.  It was the same disease, in an incipient form, of which my poor mother died.  I resolved to go and see this sufferer at once, late as the hour was.

“Did the person expect some one to go to-night?” I asked, as I passed through the hall.

“I couldn’t promise her that, sir,” was the answer.  “I did say I’d send on the message to you, and I was just coming with it, sir.  She said she’d sit up till twelve o’clock.”

“Very good,” I said.

Upon inquiry I found that the place was two miles away; and, as our old friend Simmons was still on the cab-stand, I jumped into his cab, and bade him drive me as fast as he could to No. 19 Bellringer Street.  I wanted a sense of motion, and a chance of scene.  If I had been in Guernsey, I should have mounted Madam, and had another midnight ride round the island.  This was a poor substitute for that; but the visit would serve to turn my thoughts from Julia.  If any one in London could do the man good.  I believed it was I; for I had studied that one malady with my soul thrown into it.

“We turned at last into a shabby street, recognizable even in the twilight of the scattered lamps as being a place for cheap lodging-houses.  There was a light burning in the second-floor windows of No. 19; but all the rest of the front was in darkness.  I paid Simmons and dismissed him, saying I would walk home.  By the time I turned to knock at the door, it was opened quietly from within.  A woman stood in the doorway; I could not see her face, for the candle she had brought with her was on the table behind her; neither was there light enough for her to distinguish mine.

“Are you come from Dr. Lowry’s?” she asked.

The voice sounded a familiar one, but I could not for the life of me recall whose it was.

“Yes,” I answered, “but I do not know the name of my patient here.”

“Dr. Martin Dobree!” she exclaimed, in an accent almost of terror.

I recollected her then as the person who had been in search of Olivia.  She had fallen back a few paces, and I could now see her face.  It was startled and doubtful, as if she hesitated to admit me.  Was it possible I had come to attend Olivia’s husband?

“I don’t know whatever to do!” she ejaculated; “he is very ill to-night, but I don’t think he ought to see you—­I don’t think he would.”

“Listen to me,” I said; “I do not think there is another man in London as well qualified to do him good.”

“Why?” she asked, eagerly.

“Because I have made this disease my special study,” I answered.  “Mind, I am not anxious to attend him.  I came here simply because my friend is out of town.  If he wishes to see me, I will see him, and do my best for him.  It rests entirely with himself.”