three o'clock in
the morning
Do tell me how and when ! '' `` I found it on the last day of Hugh Mainwaring 's life , within two hours after he had signed his own last will and testament . '' `` What a strange coincidence ! '' `` It was strange ; and it was my discovery on that day which formed the subject of my thoughts on the following night , the night of the murder , and which kept me pacing my room until three o'clock in the morning . '' `` Did Mr. Mainwaring know of your discovery ? '' `` No ; I had no opportunity to see him that evening until too late , even if I had chosen to broach the subject to him at that time . '' `` Might he not have discovered in some way that you had found the will ? ''