nearly opposite, sir," replied one of them. "I
know a broken window at the back where we could climb in. Then we
could get through to the front and watch from there."

"Good!" cried the Inspector. "See you are not spotted, though; and if
you hear the whistle, don't mind doing a bit of damage, but be inside
Shen-Yan's like lightning. Otherwise, wait for orders."

Inspector Ryman came in, glancing at the clock.

"Launch is waiting," he said.

"Right," replied Smith thoughtfully. "I am half afraid, though, that
the recent alarms may have scared our quarry--your man, Mason, and then
Cadby. Against which we have that, so far as he is likely to know,
there has been no clew pointing to this opium den. Remember, he thinks
Cadby's notes are destroyed."

"The whole business is an utter mystery to me," confessed Ryman. "I'm
told that there's some dangerous Chinese devil hiding somewhere in
London, and that you expect to find him at Shen-Yan's. Supposing he
uses that place, which is possible, how do you know he's there
to-night?"

"I don't," said Smith; "but it is the first clew we have had pointing
to one of his haunts, and time means precious lives where Dr. Fu-Manchu
is concerned."

"Who is he, sir, exactly, this Dr. Fu-Manchu?"

"I have only the vaguest idea, Inspector; but he is no ordinary
criminal. He is the greatest genius which the powers of evil have put
on earth for centuries. He has the backing of a political group whose
wealth is enormous, and his mission in Europe is to PAVE THE WAY! Do
you follow me? He is the advance-agent of a movement so epoch-making
that not one Britisher, and not one American, in fifty thousand has
ever dreamed of it."

Ryman stared, but made no reply, and we went out, passing down to the
breakwater and boarding the waiting launch. With her crew of three,
the party numbered seven that swung out into the Pool, and, clearing
the pier, drew in again and hugged the murky shore.

The night had been clear enough hitherto, but now came scudding
rainbanks to curtain the crescent moon, and anon to unveil her again
and show the muddy swirls about us. The view was not extensive from
the launch. Sometimes a deepening of the near shadows would tell of a
moored barge, or lights high above our heads mark the deck of a large
vessel. In the floods of moonlight gaunt shapes towered above; in the
ensuing darkness only the oily glitter of the tide occupied the
foreground of the night-p