in vain.
Long after the funeral of the Grand Duke, and at a time when I had
almost forgotten Zara el-Khala, I found myself one evening at the
opera with a distinguished French scientist and he chanced to refer
to the premature death (which had occurred a few months earlier) of
Henrik Ericksen, the Norwegian.

"A very great loss to the century, M. Max," he said. "Ericksen was as
eminent in electrical science as the Grand Duke Ivan was eminent in
the science of war. Both were stricken down in the prime of life--and
under almost identical circumstances."

"That is true," I said thoughtfully.

"It would almost seem," he continued, "as if Nature had determined to
foil any further attempts to rifle her secrets and Heaven to check
mankind in the making of future wars. Only three months after the
Grand Duke's death, the American admiral, Mackney, died at sea--you
will remember? Now, following Ericksen, Van Rembold, undoubtedly the
greatest mining engineer of the century and the only man who has
ever produced radium in workable quantities, is seized with illness
at a friend's house and expires even before medical aid can be
summoned."

"It is very strange.'

"It is uncanny."

"Were you personally acquainted with the late Van Rembold?" I asked.

"I knew him intimately--a man of unusual charm, M. Max; and I have
particular reason to remember his death, for I actually met him and
spoke to him less than an hour before he died. We only exchanged a
few words--we met on the street; but I shall never forget the subject
of our chat."

"How is that?" I asked.

"Well, I presume Van Rembold's question was prompted by his knowledge
of the fact that I had studied such subjects at one time; but he
asked me if I knew of any race or sect in Africa or Asia who
worshipped scorpions."

"_Scorpions!_" I cried. "_Ah, mon Dieu!_ monsieur say it again--
_scorpions?_"

"But yes, certainly. Does it surprise you?"

"Did it not surprise _you_?"

"Undoubtedly. I could not imagine what had occurred to account for
his asking so strange a question. I replied that I knew of no such
sect, and Van Rembold immediately changed the subject, nor did he
revert to it. So that I never learned why he had made that singular
inquiry."

You can imagine that this conversation afforded me much food for
reflection. Whilst I could think of no reason why anyone should plot
to assassinate Grand Dukes, admirals and mining engineers, the
circumstances of the s