as sharp as a razor. Its abnormality lay in a hilt of
smooth white ivory set horizontally and not vertically to the blade, as
is a rule with most knives.

Foyle carried it in the palm of his hand nearer to the light and
squinted at it from various angles. One at least of the observers
guessed his purpose. But the detective seemed dissatisfied.

"Can't see anything," he grumbled peevishly. "Ah, there you are, Grant.
I want to see whether we can make anything of this. Let me have a little
graphite, will you?"

The finger-print expert took an envelope from his pocket and handed it
to the superintendent. From it Foyle scattered fine black powder on the
hilt. A little cry of satisfaction came from his lips as he blew the
stuff away in a little dark cloud. Those in the room crowded around.

Outlined in black against the white surface of the ivory were four
finger-prints. The two centre ones were sharp and distinct, the outside
prints were fainter and more blurred.

"By Jove, that's good!" exclaimed the professor.

Foyle rubbed his chin and handed the weapon to Grant without replying.
"Get one of your men to photograph those and have them enlarged. At any
rate, it's something to go on with. It would be as well to compare 'em
with the records, though I doubt whether that will be of much use." He
drew his watch from his pocket and glanced at it. "Now, if you will
excuse me, gentlemen, I should like to have the room to myself for a
little while. And, Grant, send Green and the photographer up, and tell
Waverley to act with Bolt in examining the servants."

The room cleared. Harding lingered to exchange a few words with the
superintendent.

"I can do nothing, Mr. Foyle," he said. "From a medical point of view it
is all straightforward. There can be no question about the time and
cause of death. Good night,--or rather, good morning."

"Thank you, Mr. Harding, good morning."

His eyes were roving restlessly about the room, and he dictated the work
the photographer was to do with scrupulous care. Half a dozen times a
dazzling flash of magnesium powder lit up the place. Photographs of the
room in sections were being taken. Then with a curt order to the
photographer to return immediately to Scotland Yard and develop his
negatives, he drew up a chair to the couch and began to go methodically
through the pockets of the dead man.

Green stood by, a note-book in hand. Now and again Foyle dictated
swiftly. He was a man who knew