midnight
`` They are not at all anxious that I should fall into the hands of the police . '' `` And you are equally anxious that the world -- and more especially your daughter -- shall not know the truth , '' remarked the detective , speaking in a meaning tone . `` I have given you the alternative , and I shall now leave . At midnight I shall return -- officially -- when I hope you will have escaped by the loophole so generously allowed you by the authorities . '' `` If I fled , would you follow ? '' `` Most certainly . It would be my duty .