three
o'clock in the morning
I left the two Scotland Yard men at the opening of Cheney Lane , and continued alone to my rooms . I opened the door and let myself in quietly . And there some few hours later , began the last and most horrible phase of the case of the murder machine . * * * * * It begin -- or to be more accurate , I began to react to it -- at three o'clock in the morning . I was alone , and the rooms were dark . For hours I had sat quietly by the table , considering the significant events of the past few days . Sleep was impossible with so many unanswered questions staring into me , and so I sat there wondering .