rt reached across for the instrument and raised the receiver.
"Yes," he said--"Dr. Stuart speaking. Inspector Dunbar is here. Hold
on."

He passed the instrument to Dunbar, who had stood up on hearing his
name mentioned. "Sergeant Sowerby at Scotland Yard wishes to speak
to you, Inspector."

"Hullo," said Dunbar--"that you, Sowerby. Yes--but I arrived here
only a short time ago. What's that?--Max? Good God! what does it all
mean! Are you sure of the number--49685? Poor chap--he should have
worked with us instead of going off alone like that. But he was
always given to that sort of thing. Wait for me. I'll be with you in
a few minutes. I can get a taxi. And, Sowerby--listen! It's 'The
Scorpion' case right enough. That bit of gold found on the dead man
is not a cactus stem; it's a scorpion's tail!"

He put down the telephone and turned to Stuart, who had been listening
to the words with growing concern. Dunbar struck his open palm down
on to the table with a violent gesture.

"We have been asleep!" he exclaimed. "Gaston Max of the Paris Service
has been at work in London for a month, and we didn't know it!"

"Gaston Max!" cried Start--"then it must be a big case indeed."

As a student of criminology the name of the celebrated Frenchman was
familiar to him as that of the foremost criminal investigator in
Europe, and he found himself staring at the fragment of gold with a new
and keener interest.

"Poor chap," continued Dunbar--"it was his last. The body brought in
from Hanover Hole has been identified as his."

"What! it is the body of Gaston Max!"

"Paris has just wired that Max's reports ceased over a week ago. He
was working on the case of Sir Frank Narcombe, it seems, and I never
knew! But I predicted a long time ago that Max would play the
lone-hand game once too often. They sent particulars. The
identification disk is his. Oh! there's no doubt about it,
unfortunately. The dead man's face is unrecognizable, but it's not
likely there are two disks of that sort bearing the initials G.M. and
the number 49685. I'm going along now. Should you care to come,
doctor?"

"I am expecting a patient, Inspector," replied Stuart--"er--a special
case. But I hope you will keep me in touch with this affair?"

"Well, I shouldn't have suggested your coming to the Yard if I hadn't
wanted to do that. As a matter of fact, this scorpion job seems to
resolve itself into a case of elaborate assassination by means of
some unknown