e dacoit's knife had
bitten deeply, by reason of the fact that a warm liquid was trickling
down into my boot. Like any drunkard I stood there in the middle of the
road looking up at the vacant window where the dacoit had been, and up
at the window above the shop of J. Salaman where I knew Fu-Manchu to be.
But for some reason the latter window had been closed or almost closed,
and as I stood there this reason became apparent to me.

The sound of running footsteps came from the direction of New Oxford
Street. I turned--to see two policemen bearing down upon me!

This was a time for quick decisions and prompt action. I weighed all
the circumstances in the balance, and made the last vital choice of the
night; I turned and ran toward the British Museum as though the worst of
Fu-Manchu's creatures, and not my allies the police, were at my heels!

No one else was in sight, but, as I whirled into the Square, the red
lamp of a slowly retreating taxi became visible some hundred yards to
the left. My leg was paining me greatly, but the nature of the wound
did not interfere with my progress; therefore I continued my headlong
career, and ere the police had reached the end of Museum Street I had my
hand upon the door handle of the cab--for, the Fates being persistently
kind to me, the vehicle was for hire.

"Dr. Cleeve's, Harley Street!" I shouted at the man. "Drive like hell!
It's an urgent case."

I leaped into the cab.

Within five seconds from the time that I slammed the door and dropped
back panting upon the cushions, we were speeding westward toward the
house of the famous pathologist, thereby throwing the police hopelessly
off the track.

Faintly to my ears came the purr of a police whistle. The taxi-man
evidently did not hear the significant sound. Merciful Providence had
rung down the curtain; for to-night my role in the yellow drama was
finished.

CHAPTER XXI. CRAGMIRE TOWER

Less than two hours later, Inspector Weymouth and a party of men from
Scotland Yard raided the house in Museum Street. They found the stock
of J. Salaman practically intact, and, in the strangely appointed rooms
above, every evidence of a hasty outgoing. But of the instruments, drugs
and other laboratory paraphernalia not one item remained. I would gladly
have given my income for a year, to have gained possession of the books,
alone; for, beyond all shadow of doubt, I knew them to contain formula
calculated to revolutionize the science o