ion
for the being he conceived as existing in the Grey Room, without power
to escape from it. Thus leaning upon the bed with his arms stretched
upon it and his head perhaps sunk between them, he presently creates
that heightened temperature sufficient to arouse the destroyer. It
enters into him--how, we know not yet--and he sinks unconscious to the
floor, while the bed is quickly cold again.

"As to the four detectives--Inspector Frith and his men--pure chance
saved the life of at least one of them, and by so doing, chance also
prevented them from discovering that the bed in their midst was the seat
of all the trouble. Had one among them taken up his watch upon it, he
would certainly have died in the presence of his collaborators; but
the men sat on chairs in the corners of the room, and the chairs were
harmless. Whether their gas masks would indeed have saved them remains,
of course, to be proved. I doubt it.

"Such, my friends, were the masterpieces of the Borgia, for whom the
profoundest chemists worked willingly enough and by doing so doubtless
made their fortunes. Their poisons were so designed to act that, by
their very operation, the secrets of them were concealed, and all clues
obliterated. Chemistry knows nothing of the supernatural, yet can, as in
this case, achieve results that may well appear to be black magic.

"And if we, of this day, fail to find them out, it is easy to guess that
in their own times, much that they caused to be done was set down to the
operations of Heaven alone.

"Science will be deeply interested in your Borgia mattress, Sir Walter.
Science, I doubt not, will carefully unpick it and make a series of very
remarkable experiments; yet I make bold to believe that science may
be baffled by the cunning and forgotten knowledge of men long dust. We
shall see as to that."

He rose and bade Masters call Stephano. Then, with a few words, they
parted, and each shook the old man's hand and expressed a deep and
genuine gratitude before they did so.

"A little remains to add," said Signor Mannetti. "You shall hear what it
is to-morrow. For the moment, 'Good-night!' It has been a crowning joy
to my long life that I was able to do this service to new and valued
friends."

In the servants' hall next morning Masters related what he had heard.

"And if you ask me," he concluded, "I draw back what I thought about him
being younger than he pretends. He's older--old as the hills--older than
that hor