“You have hands and arms,” she cried, “and yet you let me go.  Be warned, then; fly from here—­” She broke off with something that sounded like a sob.

I made no move to stay her—­this beautiful accomplice of the arch-murderer, Fu-Manchu.  I heard her light footsteps pattering down the stairs, I heard her open and close the door—­the door of which Dr. Fu-Manchu held the key.  Still I stood where she had parted from me, and was so standing when a key grated in the lock and Nayland Smith came running up.

“Did you see her?” I began.

But his face showed that he had not done so, and rapidly I told him of my strange visitor, of her words, of her warning.

“How can she have passed through London in that costume?” I cried in bewilderment.  “Where can she have come from?”

Smith shrugged his shoulders and began to stuff broad-cut mixture into the familiar cracked briar.

“She might have traveled in a car or in a cab,” he said; “and undoubtedly she came direct from the house of Dr. Fu-Manchu.  You should have detained her, Petrie.  It is the third time we have had that woman in our power, the third time we have let her go free.”

“Smith,” I replied, “I couldn’t.  She came of her own free will to give me a warning.  She disarms me.”

“Because you can see she is in love with you?” he suggested, and burst into one of his rare laughs when the angry flush rose to my cheek.  “She is, Petrie why pretend to be blind to it?  You don’t know the Oriental mind as I do; but I quite understand the girl’s position.  She fears the English authorities, but would submit to capture by you!  If you would only seize her by the hair, drag her to some cellar, hurl her down and stand over her with a whip, she would tell you everything she knows, and salve her strange Eastern conscience with the reflection that speech was forced from her.  I am not joking; it is so, I assure you.  And she would adore you for your savagery, deeming you forceful and strong!”

“Smith,” I said, “be serious.  You know what her warning meant before.”

“I can guess what it means now,” he rapped.  “Hallo!”

Someone was furiously ringing the bell.

“No one at home?” said my friend.  “I will go.  I think I know what it is.”

A few minutes later he returned, carrying a large square package.

“From Weymouth,” he explained, “by district messenger.  I left him behind at the docks, and he arranged to forward any evidence which subsequently he found.  This will be fragments of the mummy.”

“What!  You think the mummy was abstracted?”

“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?”