“I quite understand.  And I only hesitated just now,” he went on, his words coming much more slowly, as though he felt he had already said too much, “because I wished to be quite sure it was no mere curiosity, but an actual sense of necessity that dictated this horrible experiment.”

“It is your safety, and that of your household, and of your sister, that is at stake,” replied the doctor.  “Once I have seen, I hope to discover whence this elemental comes, and what its real purpose is.”

Colonel Wragge signified his assent with a bow.

“And the moon will help us,” the other said, “for it will be full in the early hours of the morning, and this kind of elemental-being is always most active at the period of full moon.  Hence, you see, the clue furnished by your diary.”

So it was finally settled.  Colonel Wragge would provide the materials for the experiment, and we were to meet at midnight.  How he would contrive at that hour—­but that was his business.  I only know we both realised that he would keep his word, and whether a pig died at midnight, or at noon, was after all perhaps only a question of the sleep and personal comfort of the executioner.

“Tonight, then, in the laundry,” said Dr. Silence finally, to clinch the plan; “we three alone—­and at midnight, when the household is asleep and we shall be free from disturbance.”

He exchanged significant glances with our host, who, at that moment, was called away by the announcement that the family doctor had arrived, and was ready to see him in his sister’s room.

For the remainder of the afternoon John Silence disappeared.  I had my suspicions that he made a secret visit to the plantation and also to the laundry building; but, in any case, we saw nothing of him, and he kept strictly to himself.  He was preparing for the night, I felt sure, but the nature of his preparations I could only guess.  There was movement in his room, I heard, and an odour like incense hung about the door, and knowing that he regarded rites as the vehicles of energies, my guesses were probably not far wrong.

Colonel Wragge, too, remained absent the greater part of the afternoon, and, deeply afflicted, had scarcely left his sister’s bedside, but in response to my inquiry when we met for a moment at tea-time, he told me that although she had moments of attempted speech, her talk was quite incoherent and hysterical, and she was still quite unable to explain the nature of what she had seen.  The doctor, he said, feared she had recovered the use of her limbs, only to lose that of her memory, and perhaps even of her mind.

“Then the recovery of her legs, I trust, may be permanent, at any rate,” I ventured, finding it difficult to know what sympathy to offer.  And he replied with a curious short laugh, “Oh yes; about that there can be no doubt whatever.”

And it was due merely to the chance of my overhearing a fragment of conversation—­unwillingly, of course—­that a little further light was thrown upon the state in which the old lady actually lay.  For, as I came out of my room, it happened that Colonel Wragge and the doctor were going downstairs together, and their words floated up to my ears before I could make my presence known by so much as a cough.