bent to the oars, stealing stroke by stroke out of the grip of the
tide, and presently came to a tiny pool above the wharf structure, where
it was possible to lie undisturbed by the eager current.

Those limitations which are common to all humanity and that guile which
is peculiar to the Chinese veiled the fact from their ken that the
deserted wharf, in whose shelter they lay, was at once the roof and the
gateway of Sin Sin Wa's receiving office!

As the boat drew in to the bank, a Chinese boy who was standing on the
wharf retired into the shadows. From a spot visible down-stream but
invisible to the men in the boat, he signalled constantly with a
hurricane lantern.

Three men from New Scotland Yard were watching the house of Sin Sin Wa,
and Sin Sin Wa had given no sign of animation since, some hours earlier,
he had extinguished his bedroom light. Yet George, drifting noiselessly
up-stream, received a signal to the effect "police" while Seton Pasha
and Chief Inspector Kerry lay below the biggest dope cache in London.
Seton sometimes swore under his breath. Kerry chewed incessantly. But
George never came.

At that eerie hour of the night when all things living, from the lowest
to the highest, nor excepting Mother Earth herself, grow chilled, when
all Nature's perishable handiwork feels the touch of death--a wild,
sudden cry rang out, a wailing, sorrowful cry, that seemed to come from
nowhere, from everywhere, from the bank, from the stream; that rose and
fell and died sobbing into the hushed whisper of the tide.

Seton's hand fastened like a vise on to Kerry's shoulder, and:

"Merciful God!" he whispered; "what was it? Who was it?"

"If it wasn't a spirit it was a woman," replied Kerry hoarsely; "and a
woman very near to her end."

"Kerry!"--Seton Pasha had dropped all formality--"Kerry--if it calls
for all the men that Scotland Yard can muster, we must search every
building, down to the smallest rathole in the floor, on this bank--and
do it by dawn!"

"We'll do it," rapped Kerry.

PART FOURTH--THE EYE OF SIN SIN WA

CHAPTER XXXIII. CHINESE MAGIC

Detective-Sergeant Coombes and three assistants watched the house of Sin
Sin Wa, and any one of the three would have been prepared to swear "on
the Book" that Sin Sin Wa was sleeping. But he who watches a Chinaman
watches an illusionist. He must approach his task in the spirit of a
psychical inquirer who seeks to trap a bogus medium. The great Robert
Ho