This chapter establishes a gloomy and bitter tone through its imagery and themes. The title "The Leech" refers to Chillingworth's predatory relationship with Dimmesdale, sucking the life out of him through guilt and bad memories. Hawthorne uses metaphors comparing Chillingworth to a leech and a treasure seeker probing Dimmesdale. The gloomy setting and references to bloodletting reinforce the deadly atmosphere. Overall, the tone reveals Chillingworth's evil nature and Dimmesdale's deterioration under his influence.