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