Chapter nine explains in more detail the life of Roger Chillingworth. He has now assumed a great position in the community, and everyone trusts him. It is then suggested that Chillingworth, with his great knowledge, should help Reverend Dimmesdale, who has been getting worse as the story has gone on. Dimmesdale begins to accept treatment from Chillingworth, and they begin to develop a friendship. The two men take rooms in the same house, so Chillingworth can watch Dimmesdale. Late in the chapter, people begin to suspect Chillingworth of being a devil to take Dimmesdale's soul.
In chapter ten, a rift begins to form in the friendship between Chillingworth and Dimmesdale. Chillingworth continually tries to find the root of Dimmesdale's ailment, but to no avail. One day, Dimmesdale inquires about a strange plant, which leads to a lengthy conversation about how people may hold things in their heart, which can cause them a lot of turmoil. Chillingworth doesn't understand what is wrong with Dimmesdale until he sneaks into his room later. He goes up to Dimmesdale and opens his shirt. He then starts to rejoice after finding something there. The reader is not told what this is though.
In chapter eleven, it is discussed that as Dimmesdale becomes more and more self-loathing, the more people begin to love his sermons. Dimmesdale, meanwhile, feels that the people need to know the truth about what he has done. Every night, Dimmesdale flogs himself, and he intentionally starves himself as a way to repent. He has visions of Hester and Pearl. In these visions, Hester points first to her scarlet letter and then to Dimmesdale's chest. Dimmesdale then decides that he needs to hold a vigil on the scaffold where Hester served her sentence years before.
Dimmesdale goes to the top of the scaffold to hold his vigil. When he cries out in pain, he is sure that people will come and see him, but no one does. He is very delusional and thinks he sees many different people. He sees many people he knows coming back from the deathbed of Governor Winthrop. He laughs, then hears a laugh behind him. He looks and sees Pearl and Hester, who then stand with him on the scaffold. He tells Pearl that they will stand on the scaffold again "At the great judgement day." Pearl then sees Chillingworth over in the shadows. Dimmesdale asks Hester who he really is, but she will not tell him. Pearl acts like she'll tell him, but then tells him that shes actually punishing him for not standing with them sooner. Chillingworth then tells Dimmesdale that he had been sleep walking and he takes him home. The next day, Dimmesdale delivers his best sermon. After this, a sexton hands Dimmesdale his glove, which was found on the scaffold. They dismiss this as Satan making mischief. The people also talk about how a meteor fell in the shape of an A. They believe this as being a sign that Winthrop is an angel, and don't relate it in any way to Hester or Dimmesdale.