"I want you to drop off at the Department of Health with this
card to the commissioner. I believe you know Dr. Leslie. Well,
ask him if he knows anything about this Bridget Fallon. I will go
on up-town to the laboratory and get my apparatus ready. You
needn't come up till nine, old fellow, for I shall be busy till
then, but be sure when you come that you bring the record of this
Fallon woman if you have to beg, borrow, or steal it."

I didn't understand it, but I took the card and obeyed
implicitly. It is needless to say that I was keyed up to the
greatest pitch of excitement during my interview with the health
commissioner, when I finally got in to see him. I hadn't talked
to him long before a great light struck me, and I began to see
what Craig was driving at. The commissioner saw it first.

"If you don't mind, Mr. Jameson." he said, after I had told him
as much of my story as I could, "will you call up Professor
Kennedy and tell him I'd like very much to be present to-night
myself?"

"Certainly I will," I replied, glad to get my errand done in
first-class fashion in that way.

Things must have been running smoothly, for while I was sitting
in our apartment after dinner, impatiently waiting for half-past
eight, when the commissioner had promised to call for me and go
up to the laboratory, the telephone rang. It was Craig.

"Walter, might I ask a favour of you?" he said. "When the
commissioner comes ask him to stop at the Louis Quinze and bring