midnight
`` Poor Tom , '' he said to himself , `` poor Tom ! We were great cronies in the old times , and have had many a pleasant evening together ! '' Mr. Sheldon the dentist sat up till the small hours that night , as he had done for many nights lately . He finished his work in the torture-chamber , and went up to the common sitting-room , or drawing-room as it was called by courtesy , a little before midnight . The servants had gone to bed , for there was no regular nightly watch in the apartment of the invalid . Mrs. Halliday lay on a sofa in her husband 's room , and Nancy Woolper slept in an adjoining apartment , always wakeful and ready if help of any kind should be wanted . The house was very quiet just now .