Answer:
The doctor relentlessly and mercilessly seeks to find the root of his patient's condition. Chillingworth shows great persistence in inquiring into the most private details of Dimmesdale's life, but Dimmesdale has grown suspicious of all men and will confide in no one. Dimmesdale and Chillingsworth were talking about an unusual-looking plant. Chillingworth remarks that he found it growing on an unmarked grave and suggests that the dark weeds are the sign of the buried person's unconfessed sin.
