"You have been of inestimable assistance to us in the past, Dr.
Stuart," he said, "and I feel happy to know that we are to enjoy the
aid of your special knowledge in the present case. Will you smoke one
of my cigarettes? They are some which a friend is kind enough to
supply to me direct from Cairo, and are really quite good."

"Thanks," replied Stuart. "May I ask in what direction my services
are likely to prove available?"

The Commissioner lighted a fresh cigarette. Then from a heap of
correspondence he selected a long report typed upon blue foolscap.

"I have here," he said, "confirmation of the telegraphic report
received last night. The name of M. Gaston Max will no doubt be
familiar to you?"

Stuart nodded.

"Well," continued the Commissioner, "it appears that he has been
engaged in England for the past month endeavouring to trace the
connection which he claims to exist between the sudden deaths of
various notable people, recently--a list is appended--and some person
or organisation represented by, or associated with, a scorpion. His
personal theory not being available--poor fellow, you have heard of
his tragic death--I have this morning consulted such particulars as
I could obtain respecting these cases. If they were really cases of
assassination, some obscure poison was the only mode of death that
could possibly have been employed. Do you follow me?"

"Perfectly."