six o'clock
Once only had I known him to fail , in the case of the King of Bohemia and the Irene Adler photograph , but when I looked back to the weird business of the `` Sign of the Four , '' and the extraordinary circumstances connected with the `` Study in Scarlet , '' I felt that it would be a strange tangle indeed which he could not unravel . I left him then , still puffing at his black clay pipe , with the conviction that when I came again on the next evening I would find that he held in his hands all the clews which would lead up to the identity of the disappearing bridegroom of Miss Mary Sutherland . A professional case of great gravity was engaging my own attention at the time , and the whole of next day I was busy at the bedside of the sufferer . It was not until close upon six o'clock that I found myself free , and was able to spring into a hansom and drive to Baker Street , half afraid that I might be too late to assist at the _ dénouement _ of the little mystery . I found Sherlock Holmes alone , however , half asleep , with his long , thin form curled up in the recesses of his armchair . A formidable array of bottles and test-tubes , with the pungent , cleanly smell of hydrochloric acid , told me that he had spent his day in the chemical work which was so dear to him . `` Well , have you solved it ? ''