all but pitched him out on to the landing. We entered my
bedroom, and there, as I turned on the light, I saw that Smith's tanned
face was unusually drawn, and touched with pallor.

"It is a poisonous gas!" I said hoarsely; "in many respects identical
with chlorine, but having unique properties which prove it to be
something else--God and Fu-Manchu, alone know what! It is the fumes of
chlorine that kill the men in the bleaching powder works. We have been
blind--I particularly. Don't you see? There was no one in the
sarcophagus, Smith, but there was enough of that fearful stuff to have
suffocated a regiment!"

Smith clenched his fists convulsively.

"My God!" he said, "how can I hope to deal with the author of such a
scheme? I see the whole plan. He did not reckon on the mummy case
being overturned, and Kwee's part was to remove the plug with the aid
of the string--after Sir Lionel had been suffocated. The gas, I take
it, is heavier than air."

"Chlorine gas has a specific gravity of 2.470," I said; "two and a half
times heavier than air. You can pour it from jar to jar like a
liquid--if you are wearing a chemist's mask. In these respects this
stuff appears to be similar; the points of difference would not
interest you. The sarcophagus would have emptied through the vent, and
the gas have dispersed, with no clew remaining--except the smell."

"I did smell it, Petrie, on the stopper, but, of course, was unfamiliar
with it. You may remember that you were prevented from doing so by the
arrival of Sir Lionel? The scent of those infernal flowers must
partially have drowned it, too. Poor, misguided Strozza inhaled the
stuff, capsized the case in his fall, and all the gas--"

"Went pouring under the conservatory door, and down the steps, where
Kwee was crouching. Croxted's breaking the window created sufficient
draught to disperse what little remained. It will have settled on the
floor now. I will go and open both windows."

Nayland raised his haggard face.

"He evidently made more than was necessary to dispatch Sir Lionel
Barton," he said; "and contemptuously--you note the attitude,
Petrie?--contemptuously devoted the surplus to me. His contempt is
justified. I am a child striving to cope with a mental giant. It is
by no wit of mine that Dr. Fu-Manchu scores a double failure."

CHAPTER XIII

I WILL tell you, now of a strange dream which I dreamed, and of the
stranger things to which I awake