ristol and I looked at one another in horrified wonder.

"It's incomprehensible!" he said.

"See if the key is in the place mentioned by the Professor, Mr.
Cavanagh, whilst I break the box."

I went to a great, open bookcase, which the frantic searcher seemed
to have overlooked. Removing the bulky "Assyrian Mythology," there,
behind the volume, lay an envelope, containing a key, and a short
letter. Not caring to approach more closely to the table and to
that which lay beneath it, I was peering at the small writing, in
the semi-gloom by the bookcase, when Bristol cried--

"This box is unopenable by ordinary means! I shall have to smash
it!"

At his words, I joined him where he knelt on the floor.
Mysteriously, the chest had defied all his efforts.

"There's a pick-axe in the garden," volunteered Lester. "Shall I
bring it?"

"Yes."

The man ran off.

"I see the key is safe," said Bristol. "Possibly the letter may
throw some light upon all this."

"Let us hope so," I replied. "You might read it."

He took the letter from my hand, stepped up to the table, and by
the light of the lamp read as follows--

My Dear Cavanagh,--

It has now become apparent to me that my life is in imminent danger.
You know of the inexplicable outrages which marked my homeward
journey, and if this letter come to your hand it will be because
these have culminated in my death.

The idea of a pursuing scimitar is not new to me. This phenomenon,
which I have now witnessed three times, is fairly easy of
explanation, but its significance is singular. It is said to be
one of the devices whereby the Hashishin warn those whom they have
marked down for destruction, and is called, in the East, "The
Scimitar of Hassan."

The Hashishin were the members of a Moslem secret society, founded
in 1090 by one Hassan of Khorassan. There is a persistent tradition
in parts of the Orient that this sect still flourishes in Assyria,
under the rule of a certain Hassan of Aleppo, the Sheikh-al-jebal,
or supreme lord of the Hashishin. My careful inquiries, however,
at the time that I was preparing matter for my "Assyrian Mythology,"
failed to discover any trace of such a person or such a group.

I accordingly assumed Hassan to be a myth--a first cousin to the
ginn. I was wrong. He exists. And by my supremely rash act I
have incurred his vengeance, for Hassan of Aleppo is the
self-appointed guardian of the traditions and relics of Mohammed.
A