Chillingworth has become such a fiend that his very existence depends on Dimmesdale. When he knowingly smiles to Hester at the Election Day ceremony, he is acknowledging that he, too, will be on that ship bound for Europe, the faithful companion of the minister. It is their fate to be together. When Dimmesdale surprises the physician and climbs the scaffold to confess, Chillingworth knows the minister is about to escape him. His mental torture of the minister is his only reason for living; when his object is beyond reach, Chillingworth does, indeed cease to exist.
In the Conclusion, we discover that Chillingworth "positively withered up, shrivelled away." Obsession, vengeance, and hatred consumed him, but, despite all this, he leaves his fortune to Pearl, a child of love and passion, the living symbol and personification of the scarlet letter. Perhaps this act can, to some degree, redeem the person whose sin was the blackest.
