"Is there something else which we may learn from the experiences of Dr. Stuart? Yes! We learn that 'The Scorpion' suddenly decides that Dr. Stuart is dangerous, either because of his special knowledge (which would be interesting) or because the 'Scorpion' believes that he has become acquainted with the contents of the sealed envelope— which is not so interesting although equally dangerous for Dr. Stuart. 'The Scorpion' acts. He pays a second visit, again accompanied by Chunda Lal, who seems to be a kind of watch-dog who not only guards the person of Zara el-Kahla but who also howls when danger threatens the cowled man!

"And what is the weapon which the cowled man (who may be 'The Scorpion') uses to remove Dr. Stuart? It is a frightful weapon, my friends; it is a novel and deadly weapon. It is a weapon of which science knows nothing—a blue ray of the colour produced by a Mercury Vapour Lamp, according to Dr. Stuart who has seen it, and producing an odour like that of a blast furnace according to myself, who smelled it! Or this odour might have been caused by the fusing of the telephone; for the blue ray destroys such fragile things as telephones as easily as it destroys wood and paper! There is even a large round hole burned through the clay at the back of the study grate and through the brick wall behind it! Very well. 'The Scorpion' is a scientist and he is also the greatest menace to the world which the world has ever been called upon to deal with. You agree with me?"

Inspector Dunbar heaved a great sigh, Stuart silently accepted a cigarette from the Assistant Commissioner's box and the Assistant Commissioner spoke, slowly.

"I entirely agree with you, M. Max. Respecting this ray, as well as some one or two other minutiae, I have made a short note which we will discuss when you have completed your admirably lucid survey of the case."

"These are the things, then, which we learn from the terrible experiences of Dr. Stuart. Placing these experiences side by side with my own in Paris and in London—which we have already discussed in detail—we find that we have to deal with an organisation—the object of which is unknown—comprising among its members both Europeans ('Le Balafre' was a Frenchman, I believe), cross-breeds such as Miguel and Zara el-Khala" (Stuart winced), "one Algerian and a Hindu. It is then an organisation having ramifications throughout Europe, the East and, mon Dieu! where not? To continue. This little image"—he took up from the Commissioner's table the golden scorpion, and the broken fragment of tail—"is now definitely recognized by Dr. Stuart—who is familiar with the work of Oriental goldsmiths—to be of Chinese craftsmanship!"

"It may possibly be Tibetan," interrupted Stuart; "but it comes to the same thing."

"Very well," continued Max. "It is Chinese. We hope, very shortly, to identify a house situated somewhere within this red ink circle"—he placed his finger on a map of London which lay open on the table—"and which I know to be used as a meeting-place by members of this mysterious group. That circle, my friends, surrounds what is now known as 'Chinatown'! For the third time I return to the man of the Wu-Men Bridge; for the man of the Wu-Men Bridge was, apparently, a Chinaman! Do I make myself clear?"

"Remarkably so," declared the Assistant Commissioner, taking a fresh cigarette. "Pray continue, M. Max."

"I will do so. One of my most important investigations, in which I had the honour and the pleasure to be associated with Inspector Dunbar, led to the discovery of a dangerous group controlled by a certain 'Mr. King'——"

"Ah!" cried Dunbar, his tawny eyes sparkling with excitement, "I was waiting for that!"