"Yes, at the docks. I am sure of it; and somebody else was in the sarcophagus when it reached Rowan House. A sarcophagus, I find, is practically airtight, so that the use of the rubber stopper becomes evident—ventilation. How this person killed Strozza I have yet to learn."
"Also, how he escaped from a locked room. And what about the green mist?"
Nayland Smith spread his hands in a characteristic gesture.
"The green mist, Petrie, can be explained in several ways. Remember, we have only one man's word that it existed. It is at best a confusing datum to which we must not attach a factitious importance."
He threw the wrappings on the floor and tugged at a twine loop in the lid of the square box, which now stood upon the table. Suddenly the lid came away, bringing with it a lead lining, such as is usual in tea-chests. This lining was partially attached to one side of the box, so that the action of removing the lid at once raised and tilted it.
Then happened a singular thing.
Out over the table billowed a sort of yellowish-green cloud—an oily vapor—and an inspiration, it was nothing less, born of a memory and of some words of my beautiful visitor, came to me.
"RUN, SMITH!" I screamed. "The door! the door, for your life! Fu-Manchu sent that box!" I threw my arms round him. As he bent forward the moving vapor rose almost to his nostrils. I dragged him back and 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.