About an hour after we had found the lamps, Doctor Winchester arrived.  He had a large parcel with him, which, when unwrapped, proved to be the mummy of a cat.  With Miss Trelawny’s permission he placed this in the boudoir; and Silvio was brought close to it.  To the surprise of us all, however, except perhaps Doctor Winchester, he did not manifest the least annoyance; he took no notice of it whatever.  He stood on the table close beside it, purring loudly.  Then, following out his plan, the Doctor brought him into Mr. Trelawny’s room, we all following.  Doctor Winchester was excited; Miss Trelawny anxious.  I was more than interested myself, for I began to have a glimmering of the Doctor’s idea.  The Detective was calmly and coldly superior; but Mr. Corbeck, who was an enthusiast, was full of eager curiosity.

The moment Doctor Winchester got into the room, Silvio began to mew and wriggle; and jumping out of his arms, ran over to the cat mummy and began to scratch angrily at it.  Miss Trelawny had some difficulty in taking him away; but so soon as he was out of the room he became quiet.  When she came back there was a clamour of comments: 

“I thought so!” from the Doctor.

“What can it mean?” from Miss Trelawny.

“That’s a very strange thing!” from Mr. Corbeck.

“Odd! but it doesn’t prove anything!” from the Detective.

“I suspend my judgment!” from myself, thinking it advisable to say something.

Then by common consent we dropped the theme—­for the present.

In my room that evening I was making some notes of what had happened, when there came a low tap on the door.  In obedience to my summons Sergeant Daw came in, carefully closing the door behind him.

“Well, Sergeant,” said I, “sit down.  What is it?”

“I wanted to speak to you, sir, about those lamps.”  I nodded and waited:  he went on:  “You know that that room where they were found opens directly into the room where Miss Trelawny slept last night?”

“Yes.”

“During the night a window somewhere in that part of the house was opened, and shut again.  I heard it, and took a look round; but I could see no sign of anything.”

“Yes, I know that!” I said; “I heard a window moved myself.”

“Does nothing strike you as strange about it, sir?”

“Strange!” I said; “Strange! why it’s all the most bewildering, maddening thing I have ever encountered.  It is all so strange that one seems to wonder, and simply waits for what will happen next.  But what do you mean by strange?”

The Detective paused, as if choosing his words to begin; and then said deliberately: