“Apart from the suspicions of Miss Margaret Halley, you have no sound basis for supposing that Kazmah dealt in prohibited drugs?” he inquired.

“The evidence of Miss Halley, the letter left for her by Mrs. Irvin, and the fact that Mrs. Irvin said, in the presence of Mr. Quentin Gray, that she had ‘a particular reason’ for seeing Kazmah, point to it unmistakably, sir.  Then, I have seen Mrs. Irvin’s maid. (Mr. Monte Irvin is still too unwell to be interrogated.) The girl was very frightened, but she admitted outright that she had been in the habit of going regularly to Kazmah for certain perfumes.  She wouldn’t admit that she knew the flasks contained cocaine or veronal, but she did admit that her mistress had been addicted to the drug habit for several years.  It began when she was on the stage.”

“Ah, yes,” murmured the Assistant Commissioner; “she was Rita Dresden, was she not—­’The Maid of the Masque’ A very pretty and talented actress.  A pity—­a great pity.  So the girl, characteristically, is trying to save herself?”

“She is,” said Kerry grimly.  “But it cuts no ice.  There is another point.  After this report was made out, a message reached me from Miss Halley, as a result of which I visited Mr. Quentin Gray early this morning.”

“Dear, dear,” sighed the Assistant Commissioner, “your intense zeal and activity are admirable, Chief Inspector, but appalling.  And what did you learn?”

From an inside pocket Chief Inspector Kerry took out a plain brown paper packet containing several cigarettes and laid the packet on the table.

“I got these, sir,” he said grimly.  “They were left at Mr. Gray’s some weeks ago by the late Sir Lucien.  They are doped.”

The Assistant Commissioner, his head resting upon his hand, gazed abstractedly at the packet.  “If only you could trace the source of supply,” he murmured.

“That brings me to my last point, sir.  From Mrs. Irvin’s maid I learned that her mistress was acquainted with a certain Mrs. Sin.”

“Mrs. Sin?  Incredible name.”

“She’s a woman reputed to be married to a Chinaman.  Inspector Whiteleaf, of Vine Street, knows her by sight as one of the night-club birds—­a sort of mysterious fungus, sir, flowering in the dark and fattening on gilded fools.  Unless I’m greatly mistaken, Mrs. Sin is the link between the doped cigarettes and the missing Kazmah.”

“Does anyone know where she lives?”

“Lots of ’em know!” snapped Kerry.  “But it’s making them speak.”

“To whom do you more particularly refer, Chief Inspector?”

“To the moneyed asses and the brainless women belonging to a certain West End set, sir,” said Kerry savagely.  “They go in for every monstrosity from Buenos Ayres, Port Said and Pekin.  They get up dances that would make a wooden horse blush.  They eat hashish and they smoke opium.  They inject morphine, and they would have their hair dyed blue if they heard it was ‘being done.’”