is the man who holds the clue of this mystery, and
whom we are seeking. There is no use of arguing about it now; I tell you
that it is so. Come along, Doctor."

We started off for the cab together, leaving our informant incredulous,
but obviously uncomfortable.

"The blundering fool," Holmes said, bitterly, as we drove back to our
lodgings. "Just to think of his having such an incomparable bit of good
luck, and not taking advantage of it."

"I am rather in the dark still. It is true that the description of this
man tallies with your idea of the second party in this mystery. But why
should he come back to the house after leaving it? That is not the way
of criminals."

"The ring, man, the ring: that was what he came back for. If we have no
other way of catching him, we can always bait our line with the ring. I
shall have him, Doctor--I'll lay you two to one that I have him. I must
thank you for it all. I might not have gone but for you, and so have
missed the finest study I ever came across: a study in scarlet, eh?
Why shouldn't we use a little art jargon. There's the scarlet thread of
murder running through the colourless skein of life, and our duty is
to unravel it, and isolate it, and expose every inch of it. And now
for lunch, and then for Norman Neruda. Her attack and her bowing
are splendid. What's that little thing of Chopin's she plays so
magnificently: Tra-la-la-lira-lira-lay."

Leaning back in the cab, this amateur bloodhound carolled away like a
lark while I meditated upon the many-sidedness of the human mind.

CHAPTER V. OUR ADVERTISEMENT BRINGS A VISITOR.

OUR morning's exertions had been too much for my weak health, and I was
tired out in the afternoon. After Holmes' departure for the concert, I
lay down upon the sofa and endeavoured to get a couple of hours' sleep.
It was a useless attempt. My mind had been too much excited by all that
had occurred, and the strangest fancies and surmises crowded into
it. Every time that I closed my eyes I saw before me the distorted
baboon-like countenance of the murdered man. So sinister was the
impression which that face had produced upon me that I found it
difficult to feel anything but gratitude for him who had removed its
owner from the world. If ever human features bespoke vice of the most
malignant type, they were certainly those of Enoch J. Drebber, of
Cleveland. Still I recognized that justice must be done, and that the
depravity of the victim was n