e to enlighten him
respecting its character. It was merely a piece of silken cord, very
closely and curiously plaited. He threw it down on the table,
determined to show it to Dr. Cairn at the earliest opportunity. He was
conscious of a sort of repugnance; and prompted by this, he carefully
washed his hands as though the cord had been some unclean thing. Then,
he sat down to work, only to realise immediately, that work was
impossible until he had confided in somebody his encounter with
Ferrara.

Lifting the telephone receiver, he called up Dr. Cairn, but his father
was not at home.

He replaced the receiver, and sat staring vaguely at his open
notebook.

CHAPTER XXVI

THE IVORY HAND

For close upon an hour Robert Cairn sat at his writing-table,
endeavouring to puzzle out a solution to the mystery of Ferrara's
motive. His reflections served only to confuse his mind.

A tangible clue lay upon the table before him--the silken cord. But it
was a clue of such a nature that, whatever deductions an expert
detective might have based upon it, Robert Cairn could base none. Dusk
was not far off, and he knew that his nerves were not what they had
been before those events which had led to his Egyptian journey. He was
back in his own chamber--scene of one gruesome outrage in Ferrara's
unholy campaign; for darkness is the ally of crime, and it had always
been in the darkness that Ferrara's activities had most fearfully
manifested themselves.

What was that?

Cairn ran to the window, and, leaning out, looked down into the court
below. He could have sworn that a voice--a voice possessing a strange
music, a husky music, wholly hateful--had called him by name. But at
the moment the court was deserted, for it was already past the hour at
which members of the legal fraternity desert their business premises
to hasten homewards. Shadows were creeping under the quaint old
archways; shadows were draping the ancient walls. And there was
something in the aspect of the place which reminded him of a
quadrangle at Oxford, across which, upon a certain fateful evening, he
and another had watched the red light rising and falling in Antony
Ferrara's rooms.

Clearly his imagination was playing him tricks; and against this he
knew full well that he must guard himself. The light in his rooms was
growing dim, but instinctively his gaze sought out and found the
mysterious silken cord amid the litter on the table. He contemplated
the tel