mercifully comes but rarely.

We were heading now for that strange settlement off the West India Dock
Road, which, bounded by Limehouse Causeway and Pennyfields, and narrowly
confined within four streets, composes an unique Chinatown, a miniature
of that at Liverpool, and of the greater one in San Francisco. Inspired
with an idea which promised hopefully, I raised the speaking tube.

"Take me first to the River Police Station," I directed; "along
Ratcliffe Highway."

The man turned and nodded comprehendingly, as I could see through the
wet pane.

Presently we swerved to the right and into an even narrower street. This
inclined in an easterly direction, and proved to communicate with a wide
thoroughfare along which passed brilliantly lighted electric trams. I
had lost all sense of direction, and when, swinging to the left and to
the right again, I looked through the window and perceived that we were
before the door of the Police Station, I was dully surprised.

In quite mechanical fashion I entered the depot. Inspector Ryman, our
associate in one of the darkest episodes of the campaign with the Yellow
Doctor two years before, received me in his office.

By a negative shake of the head, he answered my unspoken question.

"The ten o'clock boat is lying off the Stone Stairs, Doctor," he said,
"and co-operating with some of the Scotland Yard men who are dragging
that district--"

I shuddered at the word "dragging"; Ryman had not used it literally, but
nevertheless it had conjured up a dread possibility--a possibility in
accordance with the methods of Dr. Fu-Manchu. All within space of an
instant I saw the tide of Limehouse Reach, the Thames lapping about
the green-coated timbers of a dock pier; and rising--falling--sometimes
disclosing to the pallid light a rigid hand, sometimes a horribly
bloated face--I saw the body of Nayland Smith at the mercy of those oily
waters. Ryman continued:

"There is a launch out, too, patrolling the riverside from here to
Tilbury. Another lies at the breakwater"--he jerked his thumb over his
shoulder. "Should you care to take a run down and see for yourself?"

"No, thanks," I replied, shaking my head. "You are doing all that can be
done. Can you give me the address of the place to which Mr. Smith went
last night?"

"Certainly," said Ryman; "I thought you knew it. You remember Shen-Yan's
place--by Limehouse Basin? Well, further east--east of the Causeway,
between Gill Street and Th