"Your case to date, Mr. Smith," continued Fletcher, remaining with
hands locked behind him, staring from the window, "reads something like
this, I believe: A brass box, locked, contents unknown, has come into
your possession. It stands now upon the table there. It was brought
from Tibet by a man who evidently thought that it had something to
do with the Si-Fan. He is dead, possibly by the agency of members of
this group. No arrests have been made. You know that there are people
here in London who are anxious to regain the box. You have theories
respecting the identity of some of them, but there are practically no
facts."

Nayland Smith nodded his head.

"Exactly!" he snapped.

"Inspector Weymouth, here," continued Fletcher, "has put me in
possession of such facts as are known to him, and I believe that I
have had the good fortune to chance upon a valuable one."

"You interest me, Sergeant Fletcher," said Smith. "What is the nature
of this clue?"

"I will tell you," replied the other, and turned briskly upon his heel
to face us.

He had a dark, clean-shaven face, rather sallow complexion, and
deep-set, searching eyes. There was decision in the square, cleft chin
and strong character in the cleanly chiseled features. His manner was
alert.