ell-tale weapons."

Only three cabs were on the rank, and, as we entered the first,
something hissed past my ear, missed both Smith and me by a miracle,
and, passing over the roof of the taxi, presumably fell in the enclosed
garden occupying the center of the square.

"What was that?" I cried.

"Get in--quickly!" Smith rapped back. "It was attempt number one!
More than that I cannot say. Don't let the man hear. He has noticed
nothing. Pull up the window on your side, Petrie, and look out behind.
Good! We've started."

The cab moved off with a metallic jerk, and I turned and looked back
through the little window in the rear.

"Someone has got into another cab. It is following ours, I think."

Nayland Smith lay back and laughed unmirthfully.

"Petrie," he said, "if I escape alive from this business I shall know
that I bear a charmed life."

I made no reply, as he pulled out the dilapidated pouch and filled his
pipe.

"You have asked me to explain matters," he continued, "and I will do so
to the best of my ability. You no doubt wonder why a servant of the
British Government, lately stationed in Burma, suddenly appears in
London, in the character of a detective. I am here, Petrie--and I bear
credentials from the very highest sources--because, quite by accident,
I came upon a clew. Following it up, in the ordinary course of
routine, I obtained evidence of the existence and malignant activity of
a certain man. At the present stage of the case I should not be
justified in terming him the emissary of an Eastern Power, but I may
say that representations are shortly to be made to that Power's
ambassador in London."

He paused and glanced back towards the pursuing cab.

"There is little to fear until we arrive home," he said calmly.
"Afterwards there is much. To continue: This man, whether a fanatic
or a duly appointed agent, is, unquestionably, the most malign and
formidable personality existing in the known world today. He is a
linguist who speaks with almost equal facility in any of the civilized
languages, and in most of the barbaric. He is an adept in all the arts
and sciences which a great university could teach him. He also is an
adept in certain obscure arts and sciences which no university of
to-day can teach. He has the brains of any three men of genius.
Petrie, he is a mental giant."

"You amaze me!" I said.

"As to his mission among men. Why did M. Jules Furneaux fall dead in a
Paris