As I was not "coming back to them" quite in the sense intended I felt a
little guilty, but reserved my confidences for Thorndyke's ear and
replied in polite generalities. Then Polton fetched the tea-pot from the
laboratory, made up the fire and departed, and Thorndyke and I subsided,
as of old, into our respective arm-chairs.

"And whence do you spring from in this unexpected fashion?" my colleague
asked. "You look as if you had been making professional visits."

"I have. The base of operations is in Lower Kennington Lane."

"Ah! Then you are 'back once more on the old trail'?"

"Yes," I answered, with a laugh, "'the old trail, the long trail, the
trail that is always new.'"

"And leads nowhere," Thorndyke added grimly.

I laughed again; not very heartily, for there was an uncomfortable
element of truth in my friend's remark, to which my own experience bore
only too complete testimony. The medical practitioner whose lack of
means forces him to subsist by taking temporary charge of other men's
practices is apt to find that the passing years bring him little but
grey hairs and a wealth of disagreeable experience.

"You will have to drop it, Jervis; you will, indeed," Thorndyke resumed
after a pause. "This casual employment is preposterous for a man of your
class and professional attainments. Besides, are you not engaged to be
married and to a most charming girl?"