The Assistant Commissioner handed a pencilled slip to Dunbar. It read
as follows:--

"Gaston Max in London. Scorpion, Narcombe. No report since 30th ult.
Fear trouble. Identity-disk G. M. 49685."

"But, sir," said Dunbar--"this is exactly what Sowerby told me!"

"Quite so. That is the really extraordinary feature of the affair.
Because, you see, Inspector, I only finished decoding this message
at the very moment that you knocked at my door!"

"But----"

"There is no room for a 'but,' Inspector. This confidential message
from Paris reached me ten minutes ago. You know as well as I know that
there is no possibility of leakage. No one has entered my room in the
interval, yet you tell me that Sergeant Sowerby communicated this
information to you, by telephone, half an hour ago."

Dunbar was tapping his teeth with the pencil. His amazement was too
great for words.

"Had the message been a false one," continued the Commissioner, "the
matter would have been resolved into a meaningless hoax, but the
message having been what it was, we find ourselves face to face with
no ordinary problem. Remember, Inspector, that voices on the telephone
are deceptive. Sergeant Sowerby has marked vocal mannerisms----"