Dunbar and Sowerby were staring at one another amazedly.

“It was in the corner of a public house billiard-room,” added the Frenchman, with twinkling eyes; “I adopted the ill-used name of Levinsky on that occasion."...

Dunbar began to punch his left palm and to stride up and down the floor; whilst Sowerby, his blue eyes opened quite roundly, watched M. Max as a schoolboy watches an illusionist.

“Therefore,” continued M. Max, “I shall ask you to have a party ready on Tuesday night in Limehouse Causeway—­suitably concealed, of course; and as I am almost sure that the haunt of Mr. King is actually upon the riverside (I heard one little river sound as I was coming away) a launch party might cooperate with you in affecting the raid.”

“The raid!” said Dunbar, turning from a point by the window, and looking back at the Frenchman.  “Do you seriously tell me that we are going to raid Mr. King’s on Tuesday night?”

“Most certainly,” was the confident reply.  “I had hoped to form one of the raiding party; but nom d’un nom!”—­he shrugged, in his graceful fashion—­“I must be one of the rescued!”

“Of the rescued!”

“You see I visited that establishment as a smoker of opium"...

“You took that risk?”

“It was no greater risk than is run by quite a number of people socially well known in London, my dear Inspector Dunbar!  I was introduced by an habitue and a member of the best society; and since nobody knows that Gaston Max is in London—­that Gaston Max has any business in hand likely to bring him to London—­pardieu, what danger did I incur?  But, excepting the lobby—­the cave of the dragon (a stranger apartment even than that in the Rue St. Claude) and the Chinese cubiculum where I spent the night—­mon dieu! what a night!—­I saw nothing of the establishment"...

“But you must know where it is!” cried Dunbar.

“I was driven there in a closed limousine, and driven away in the same vehicle"...

“You got the number?”

“It was impossible.  These are clever people!  But it must be a simple matter, Inspector, to trace a fine car like that which regularly appears in those east-end streets?”

“Every constable in the division must be acquainted with it,” replied Dunbar, confidently.  “I’ll know all about that car inside the next hour!”

“If on Tuesday night you could arrange to have it followed,” continued M. Max, “it would simplify matters.  What I have done is this:  I have bought the man, Soames—­up to a point.  But so deadly is his fear of the mysterious Mr. King that although he has agreed to assist me in my plans, he will not consent to divulge an atom of information until the raid is successfully performed.”

“Then for heaven’s sake what is he going to do?”

“Visitors to the establishment (it is managed by a certain Mr. Ho-Pin; make a note of him, that Ho-Pin) having received the necessary dose of opium are locked in for the night.  On Tuesday, Soames, who acts as valet to poor fools using the place, has agreed—­for a price—­to unlock the door of the room in which I shall be"...