“The case is clear,” he said, “from first to last, provided you can supply us with a final detail, Miss Vaughan.”

“What is that?” she asked.

“Did you write that note to Swain in your own room?”

“Yes.”

“And will you show me the table at which you wrote it?”

“Certainly,” and she opened the door.  “Come in.  I wrote it at that little desk by the window.”

Godfrey walked to it, picked up a blotting-book which lay upon it, and turned over the leaves.

“Ah!” he said, after a moment.  “I was sure of it.  Here is the final link.  Have you a small hand-mirror, Miss Vaughan?”

She brought one from her toilet-table and handed it to him in evident astonishment.

“What do you see in the mirror?” he asked, and held a page of the blotting-book at an angle in front of it.

Miss Vaughan uttered an exclamation of surprise, as she read the words reflected there: 

MR. FREDERIC SWAIN,
1010 Fifth Avenue,
New York City.

If not at this address,
please try the Calumet Club.

“‘Tall oaks from little acorns grow,’” quoted Godfrey, tossing the book back upon the desk.  “But for the fact that you blotted the envelope, Miss Vaughan, young Swain would never have been accused of murder.”

“I do not understand,” she murmured.

“Don’t you see,” he pointed out, “the one question which we have been unable to answer up to this moment has been this:  how did Silva know you were going to meet Swain?  He had to know it, and know it several hours before the meeting, in order to have those finger-prints ready.  I concluded, at last, that there must be a blotting-book—­and there it is.”

Miss Vaughan stared at him.

“You seem to be a very wonderful man!” she said.

Godfrey laughed.

“It is my every-day business to reconstruct mysteries,” he said.  “Shall I reconstruct this one?”

“Please do!” she begged, and motioned us to be seated.

Godfrey’s face was glowing with the sort of creative fire which, I imagine, illumines the poet’s brow at the moment of inspiration.

“Where did you first meet Silva?” he asked.

“In Paris.”

“What was he doing there?”

“He was practising mysticism.  My father went to consult him; he was much impressed by him, and they became very intimate.”

“And Silva, of course, at once saw the possibilities of exploiting an immensely rich old man, whose mind was failing.  So he comes here as his instructor in Orientalism; he does some very marvellous things; by continued hypnosis, he gets your father completely under his control.  He secures a promise of this estate and a great endowment; he causes your father to make a will in which these bequests are specifically stated.  Then he hesitates, for during his residence in this house, a new desire has been added to the