For a while she sat, making some notes or memoranda.  Then putting them away, she sent for the faithful servants.  I thought that she had better have this interview alone, and so left her.  When I came back there were traces of tears in her eyes.

The next phase in which I had a part was even more disturbing, and infinitely more painful.  Late in the afternoon Sergeant Daw came into the study where I was sitting.  After closing the door carefully and looking all round the room to make certain that we were alone, he came close to me.

“What is it?” I asked him.  “I see you wish to speak to me privately.”

“Quite so, sir!  May I speak in absolute confidence?”

“Of course you may.  In anything that is for the good of Miss Trelawny—­ and of course Mr. Trelawny—­you may be perfectly frank.  I take it that we both want to serve them to the best of our powers.”  He hesitated before replying: 

“Of course you know that I have my duty to do; and I think you know me well enough to know that I will do it.  I am a policeman—­a detective; and it is my duty to find out the facts of any case I am put on, without fear or favour to anyone.  I would rather speak to you alone, in confidence if I may, without reference to any duty of anyone to anyone, except mine to Scotland Yard.”

“Of course! of course!” I answered mechanically, my heart sinking, I did not know why.  “Be quite frank with me.  I assure you of my confidence.”

“Thank you, sir.  I take it that what I say is not to pass beyond you—­ not to anyone.  Not to Miss Trelawny herself, or even to Mr. Trelawny when he becomes well again.”

“Certainly, if you make it a condition!” I said a little more stiffly.  The man recognised the change in my voice or manner, and said apologetically: 

“Excuse me, sir, but I am going outside my duty in speaking to you at all on the subject.  I know you, however, of old; and I feel that I can trust you.  Not your word, sir, that is all right; but your discretion!”

I bowed.  “Go on!” I said.  He began at once: 

“I have gone over this case, sir, till my brain begins to reel; but I can’t find any ordinary solution of it.  At the time of each attempt no one has seemingly come into the house; and certainly no one has got out.  What does it strike you is the inference?”

“That the somebody—­or the something—­was in the house already,” I answered, smiling in spite of myself.

“That’s just what I think,” he said, with a manifest sigh of relief.  “Very well!  Who can be that someone?”

“‘Someone, or something,’ was what I said,” I answered.

“Let us make it ‘someone,’ Mr. Ross!  That cat, though he might have scratched or bit, never pulled the old gentleman out of bed, and tried to get the bangle with the key off his arm.  Such things are all very well in books where your amateur detectives, who know everything before it’s done, can fit them into theories; but in Scotland Yard, where the men aren’t all idiots either, we generally find that when crime is done, or attempted, it’s people, not things, that are at the bottom of it.”