What was Chillingworth's plot in The Scarlet Letter?

Roger Chillingworth in The Scarlet Letter was Hester Prynne's estranged husband. In order to find out who has been his wife's secret lover, he poses as the town's doctor. In short order the townsfolk trust him with their deepest concerns, even the pastor...who confesses all. In order to persecute the Reverend he moves in with him in order to use his knowledge of psychology to intensify the Reverend's guilt.