" he said, "your visit has been of great interest
to me. If I can be of any further assistance, pray do not hesitate to
call upon me."

CHAPTER XXIII. ON THE TRAIL

Inspector Jacks studied the brass plate for a moment, and then rang
the patients' bell. The former, he noticed was very much in want of
cleaning, and for a doctor's residence there was a certain lack of
smartness about the house and its appointments which betokened a limited
practice. The railing in front was broken, and no pretence had been made
at keeping the garden in order. Inspector Jacks had time to notice these
things, for it was not until after his second summons that the door was
opened by Dr. Whiles himself.

"Good morning!" the latter said tentatively. Then, with a slight air of
disappointment, he recognized his visitor.

"Good morning, doctor!" Inspector Jacks replied. "You haven't forgotten
me, I hope? I came down to see you a short time ago, respecting the
man who was knocked down by a motor car and treated by you on a certain
evening."

The doctor nodded.

"Will you come in?" he asked.

He led the way into a somewhat dingy waiting room. A copy of _The
Field_, a month old, a dog-eared magazine, and a bound volume of _Good
Words_ were spread upon the table. The room itself, except for a few
chairs, was practically bare.

"I do not wish to take up too much of your time, Dr. Whiles," the
Inspector began,--

The doctor laughed shortly.

"You needn't bother about that," he said. "I'm tired of making a bluff.
My time isn't any too well occupied."

The Inspector glanced at his watch,--it was a few minutes past twelve.

"If you are really not busy," he said, "I was about to suggest to you
that you should come back to town with me and lunch. I do not expect,
of course, to take up your day for nothing," he continued. "You will
understand, as a professional man, that when your services are required
by the authorities, they expect and are willing to pay for them."

"But what use can I be to you?" the doctor asked. "You know all about
the man whom I fixed up on the night of the murder. There's nothing more
to tell you about that. I'd as soon go up to town and lunch with you as
not, but if you think that I've anything more to tell you, you'll only
be disappointed."

The Inspector nodded.

"I'm quite content to run the risk of that," he said. "Of course," he
continued, "it does not follow in the least that this person was in any
way c