We can find the bulk of the action of Nathaniel Hawthorne's The Scarlet Letterin the period of time that corresponds with Chillingworth's entrance in the settlement as a physician and the seven years that go by before he and Hester speak another word again.
At this point we know that Chillingworth has become Dimmesdale's leech. He has injected enough poison, doubt, guilt, and fear in the minister's heart to literally break the man. However, all through this seven years, we know that Hester's life has changed somewhat for the better.
Hester now lives in the community and enjoys a very well-liked reputation. She is now referred to as "our Hester" by the villagers and her scarlet letter has become iconic to both the townsmen, and herself. The only difference now is that her scarlet letter does not instill the feelings of anger and resentment that it does when Hester first wears it. In fact, Hester never removes it and it seems as if she never will. Her letter is now a part of her reality as a human being, and as a woman. She is the woman with the scarlet letter.
During this time we also witness Pearl's growing curiosity as to the meaning of the letter, and as to why Reverend Dimmesdale continuously places his hand over his heart. This symbolizes Hester's sad reminder that, no matter what value she gives her letter, there will always be Pearl to remind her of her sin...and it seems as if that is precisely what Pearl intends to do.
As for Dimmesdale, his health continues to break down terribly and he is completely consumed by guilt even when Hester has managed to live life with the scarlet letter. At this point we can assume that Dimmesdale was either sincerely sorry for fathering Hester's child, or blowing the matter out of proportion. In any way, it is Chillingworth who acts as the causative factor behind Dimmesdale's depressed life.
The technique of moving a plot forward by a number of years is effective in breaking with the ongoing story lines to avoid a lengthy and thick narrative. When all the information that is to be given about a character suffices enough to establish conclusions, an author may move the plot forward so that the reader can confirm whether the conclusions would match their expectations of the plot or not. It is a good technique for lengthy novels, for it keeps the action fresh. It is a very effective technique in this particular novel because the four principal characters are fully profiled and their lives are fully narrated from beginning to end.