“There is one other point,” said Inspector MacDonald.  “You met Mr. Douglas in a boarding house in London, did you not, and became engaged to him there?  Was there any romance, anything secret or mysterious, about the wedding?”

“There was romance.  There is always romance.  There was nothing mysterious.”

“He had no rival?”

“No, I was quite free.”

“You have heard, no doubt, that his wedding ring has been taken.  Does that suggest anything to you?  Suppose that some enemy of his old life had tracked him down and committed this crime, what possible reason could he have for taking his wedding ring?”

For an instant I could have sworn that the faintest shadow of a smile flickered over the woman’s lips.

“I really cannot tell,” she answered.  “It is certainly a most extraordinary thing.”

“Well, we will not detain you any longer, and we are sorry to have put you to this trouble at such a time,” said the inspector.  “There are some other points, no doubt; but we can refer to you as they arise.”

She rose, and I was again conscious of that quick, questioning glance with which she had just surveyed us.  “What impression has my evidence made upon you?” The question might as well have been spoken.  Then, with a bow, she swept from the room.

“She’s a beautiful woman—­a very beautiful woman,” said MacDonald thoughtfully, after the door had closed behind her.  “This man Barker has certainly been down here a good deal.  He is a man who might be attractive to a woman.  He admits that the dead man was jealous, and maybe he knew best himself what cause he had for jealousy.  Then there’s that wedding ring.  You can’t get past that.  The man who tears a wedding ring off a dead man’s—­What do you say to it, Mr. Holmes?”

My friend had sat with his head upon his hands, sunk in the deepest thought.  Now he rose and rang the bell.  “Ames,” he said, when the butler entered, “where is Mr. Cecil Barker now?”

“I’ll see, sir.”

He came back in a moment to say that Barker was in the garden.

“Can you remember, Ames, what Mr. Barker had on his feet last night when you joined him in the study?”

“Yes, Mr. Holmes.  He had a pair of bedroom slippers.  I brought him his boots when he went for the police.”

“Where are the slippers now?”

“They are still under the chair in the hall.”

“Very good, Ames.  It is, of course, important for us to know which tracks may be Mr. Barker’s and which from outside.”

“Yes, sir.  I may say that I noticed that the slippers were stained with blood—­so indeed were my own.”

“That is natural enough, considering the condition of the room.  Very good, Ames.  We will ring if we want you.”

A few minutes later we were in the study.  Holmes had brought with him the carpet slippers from the hall.  As Ames had observed, the soles of both were dark with blood.