From the time that Chillingworth moves into with Dimmesdale (at the suggestion of the townspeople) they are always together. Dimmesdale feels the doctor is just trying to take car of him, while we know Chillingworth is just trying to find out his dark secrets. Finally one night, filled with guilt, Dimmesdale climbs the scaffold. Though it is in the safety of night, he is standing on the same scaffold Hester and Pearl were on at the beginning of the book. Dimmesdale stands on the scaffold again at the end of the novel to confess that he is in fact Pearl's father. The scaffold is the only place where Dimmesdale can't reach him.