But ere I had time to begin there was an interruption.  Dimly, a telephone bell rang.  I could hear the voice of Marie, Isobel’s maid, answering the call then: 

“Mr. Coverly to speak to you, madam,” said Marie, entering the room.

“He must have only just heard the news!” cried Isobel, rising swiftly and going out.

Consumed by impatience, I walked up and down the dainty apartment listening to Isobel’s muffled voice speaking in the lobby.  Twice I went to the window and peered down into the street, expecting to see the thick-set figure of Inspector Gatton approaching.  My frame of mind was peculiar and troubled.  Gatton’s inquiries pointed unmistakably to a suspicion that Sir Marcus’s last hours had been spent, if not actually with, at any rate near to Isobel.  And since the man who would most directly profit by the baronet’s death happened also to be Isobel’s fiance, I foresaw a dreadful ordeal for both if Eric Coverly was not in a position to establish an alibi.

I had been about to ask her if Coverly had been in her company on the previous night when the interruption had occurred.  Now if Gatton should arrive and find me in Isobel’s flat, what construction would he put upon my presence?

Yet again I went to the window and peered anxiously up and down the street.  Every cab that approached I expected to contain the inspector, and I heaved a sigh of relief as one after another passed the door.  Pedestrians who turned the distant corner I scrutinized closely and was so employed when Isobel came running back to the room.

All her color had fled and her eyes were wide and fear-stricken.

“Oh, Jack, Jack!” she cried, “it is horrible, horrible!  Eric is at his solicitors’ and they tell him that suspicion is bound to fall on him!  It’s preposterous—­unthinkable.  It must have been some fiend who committed such a crime, not a human being—­”

“Then,” I interrupted excitedly, “Coverly was not with you last night?”

“No!  That is the crowning tragedy of it all.  He ’phoned me early in the evening saying that he had an unavoidable business appointment to keep.  From the tone of his voice—­”

She ceased speaking abruptly, and stared at me rather wildly.

“Isobel,” I said, “you should surely know that you can trust your life to me—­and the life of any one dear to you.”

She quickly laid her hand on my arm and her face flushed sweetly.  I fear I had infused my words with an ardor which exhibited at an earlier and more opportune moment might have changed the course of both our lives.

“Of course I know, Jack,” she said.  “But I am so frightened that I distrust my very self.  Well, then, I thought that I noticed a change in Eric’s manner last night—­in the tone of his voice.  In fact I asked him if I had done anything of which he had disapproved.”  She gave me a quick little embarrassed glance.  “He is somewhat exacting, you know.  He laughed at the idea, but in rather a forced way, it seemed.  Then he arranged to meet me for lunch at the Carlton to-day.”