He was out of town, yachting, but his partner came into the clerks' office to see me. I told him that my business with Mr. Delverton was private.

This partner, I discovered, was Kellner, who had formerly been a clerk in the firm. He was the man who, with the junior, had been the last to leave the office on the night of the tragedy. He was worth a little attention, and I spent two days making inquiries about him. He was as smart a man of business as could be found within a mile radius of the Royal Exchange, I was informed, a wonderful linguist, with a profound knowledge of financial matters. Now he was a wealthy man, but three years ago he had been in very low water.

This discovery sent me to Twickenham again. I said nothing about Kellner having become a partner in Delverton Brothers'; I merely asked Southey whether he had satisfactorily accounted for his time on the fatal night.

"Didn't I tell you?" said Southey. "Oh, yes, he had an absolute alibi; so had the youth Small. I made them my first business."

I did not call on Dr. Morrison, but I went to his neighborhood, and asked a few questions. Everybody spoke well of the doctor, which, of course, might mean much or little, and I was fortunate enough to see him with his wife in a motor. He looked like a doctor, a forceful and self-reliant man, not one to lose his head or give himself away. He would be likely to carry through any enterprise he set his mind to. His wife, without being beautiful, was attractive, the kind of woman you begin to call pretty after you have known her a little while.

That night I wrote a full report to Christopher Quarles with my own comments in the margin, and three days later I had a wire from Zena, saying they were returning to Chelsea at once.

There was no need to ask the professor whether the case interested him or not. He began by being complimentary about my report, praised my astuteness in not calling upon the doctor, and he made me give him a verbal description of Morrison and his wife.

"Of course, Wigan, looks count for nothing, but they are often misleading evidence, and we are told to beware of that man of whom every one speaks well. The most saintly individual I ever knew had a strong likeness to a notorious criminal I once saw, and on a slight acquaintance you and I would probably have trusted Cleopatra or Helen of Troy, neither of them very estimable women, I take it. Now apparently this doctor and his wife are near the center of this mystery."

"It seems so, but—"

"Believe me, I am making no accusation," he interrupted; "indeed, I am more inclined to argue that they occupy an eccentric point within the circle rather than the true center. Still, we must not overlook one or two facts which you have duly emphasized in your report. The rivalry between Morrison and Farrell does supply, as you say, a motive for the crime, if crime it was, and it is the only motive that is apparent. Again, a doctor could obtain and make use of poison with less risk than most men. And, again, it is curious the doctor should call on Farrell on that particular day. The visit might be a subtle move to establish his innocence. True, according to Southey, his time after the visit was accounted for, but how about the time before the visit? Farrell had already left the office an hour, and might have met Morrison."