then she came back to the point where , perhaps , she ought to have begun , and that was to knock at the door against which the stranger had leaned ; but this proved useless -- for though she knocked ten or twelve times in succession , no one answered , and some of the neighbors , who put their noses out of their windows or were brought to their doors by the noise , had assured her that that house , all the openings of which were tightly closed , had not been inhabited for six months .