“There was some one watching it,” Arnold went on.  “I told you.  I saw your lips quiver with fear.  Then your husband came in and took you away.  You left me there in the room alone.  I was to wait for you.  While I was there, one of the men, who had been watching, stole up through your garden to the very window.  I saw his face.  I saw his hand upon the window-sill with that strange ring upon his finger.  You have not forgotten?”

“Forgotten!” she repeated.  “As though that were possible!”

“Very well,” Arnold continued.  “Now let me ask you to remember another evening, only last week, the night I dined with your brother.  I brought you home from the Empire and we found that your sitting-room had been entered from that same window.  The door was locked and we all thought that burglars must be there.  I climbed in at the window from the garden.  You know what I found.”

All the time she seemed to have been making an effort to listen to him unconcernedly.  At this point, however, she broke down.  She abandoned her attempt at continuing her luncheon.  She looked up at him and he could see that she was trembling.

“Don’t go on!” she begged; “please don’t!”

“I must,” he insisted.  “These things have taken possession of me.  I cannot sleep or rest for thinking of them.”

“For my sake,” she implored, “try and forget!”

He shook his head.

“It isn’t possible,” he said simply.  “I am not made like that.  Even if you hate me for it, I must go on.  You know what I found in your sitting-room that night.”

“But this is cruel!” she murmured.

“I found a dead man, a man who, to all appearance, had been murdered in there.  Not only that, but there must have been people close at hand who were connected with him in some way, or who were responsible for the crime.  We left the room for five minutes, and when we came back he had disappeared.  All that we can judge as to what became of him is that that same night a dead man was left in a taxicab, not far away, by an unknown man whom as yet the police have failed to find.”

“But this is all too horrible!” she murmured.  “Why, do you remind me of it?”

“Because I must,” he went on.  “Listen.  There are other things.  This man Starling, for instance, whom I met at your house, and who is suspected of the murder of Rosario—­both your brother and you seem to be trying to shield him.  I don’t understand it; I can’t understand it.  Your brother talked to me strangely the night I dined with him, but half the time I felt that he was not serious.  I do not for a moment believe that he would stoop to any undignified or criminal action.  I believe in him as I do in you.  Yet if Starling is guilty, why do you both protect him?”

“Is there anything else?” she faltered.

“There is the final thing,” he reminded her; “the reason why I have mentioned these matters to you at all—­I mean the disappearance of Mr. Weatherley.  Supposing he does not come back, how am I to keep silent, knowing all that I know, knowing that he was living in a house surrounded by mysteries?  I hate my suspicions.  They are like ugly shadows which follow me about.  I like and admire your brother, and you—­you know—­”