h B. Cave_

[Sidenote: Four lives lay helpless before the murder machine, the
uncanny device by which hypnotic thought-waves are filtered through
men's minds to mold them into murdering tools!]

It was dusk, on the evening of December 7, 1906, when I first
encountered Sir John Harmon. At the moment of his entrance I was
standing over the table in my study, a lighted match in my cupped hands
and a pipe between my teeth. The pipe was never lit.

I heard the lower door slam shut with a violent clatter. The stairs
resounded to a series of unsteady footbeats, and the door of my study
was flung back. In the opening, staring at me with quiet dignity, stood
a young, careless fellow, about five feet ten in height and decidedly
dark of complexion. The swagger of his entrance branded him as an
adventurer. The ghastly pallor of his face, which was almost colorless,
branded him as a man who has found something more than mere adventure.

"Doctor Dale?" he demanded.

"I am Doctor Dale."

He closed the door of the room deliberately, advancing toward me with
slow steps.

"My name is John Harmon--Sir John Harmon. It is unusual, I suppose," he
said quietly, with a slight shrug, "coming at this late hour. I won't
keep you long."

He faced me silently. A single glance at those strained features
convinced me of the reason for his coming. Only one thing can bring such
a furtive, restless stare to a man's eyes. Only one thing--fear.

"I've come to you. Dale, because--" Sir John's fingers closed heavily
over the edge of the table--"because I am on the verge of going mad."

"From fear?"

"From fear, yes. I suppose it is easy to discover. A single look at
me...."

"A single look at you," I said simply, "would convince any man that you
are deadly afraid of something. Do you mind telling me just what it is?"

* * * * *

He shook his head slowly. The swagger of the poise was gone; he stood
upright now with a positive effort, as if the realization of his
position had suddenly surged over him.

"I do not know," he said quietly. "It is a childish fear--fear of the
dark, you may call it. The cause does not matter; but if something does
not take this unholy terror away, the effect will be madness."

I watched him in silence for a moment, studying the shrunken outline of
his face and the unsteady gleam of his narrowed eyes. I had seen this
man before. All London had seen him. His face was constantly app