"There remains the priest, the Rev. Septimus May. He neither lay on the bed, nor sat upon it. But what did he do? He clearly knelt beside it a long time, engaged in prayer. Nothing more natural than that he should stretch his arms over the mattress; bury his face in his hands, and so remain in commune with the Almighty, uttering petition after petition 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 horror in the Grey Boom. He's a demon; and he's killed the old dog; and I believe he's a Borge himself if the truth was known."