ten o'clock
`` They wo n't , '' laughed Holmes . `` They 'll spend their time looking for some impecunious member of the smart set who might have done the job . They always try to find the sensational clew first , and by day after to-morrow morning four or five poor but honest members of the four-hundred will find when they read the morning papers that they are under surveillance , while I , knowing exactly what has happened will have all the start I need . I have already offered my services , and by ten o'clock to-morrow morning they will be accepted , as will also those of half a hundred other detectives , professional and amateur . At eleven I will visit the opera-house , where I expect to find the incriminating letter on the floor , or if the cleaning women have already done their work , which is very doubtful , I will find it later among the sweepings of waste paper in the cellar of the opera-house . Accompanied by two plain-clothes men from headquarters I will then proceed to Nervy 's quarters , and , if he is really sincere in his desire to go to jail for a protracted period , we shall find him there giving an imitation of a gloat over his booty . '' `` And suppose the incriminating letter is not there ? ''