The novel opens in Boston, where Hester Prynne stands on a scaffold, holding her infant daughter, Pearl. She is being publicly shamed for committing adultery, though she refuses to reveal the identity of the child’s father. As punishment, she is forced to wear a scarlet letter "A" on her chest as a symbol of her sin. Hester’s long-lost husband, now calling himself Roger Chillingworth, arrives in the colony and vows to discover the identity of Pearl’s father.

Despite the community’s scorn, Hester remains strong, supporting herself and Pearl through her skill as a seamstress. Meanwhile, the town’s revered minister, Arthur Dimmesdale, is tormented by his secret guilt—he is Pearl’s father but lacks the courage to confess. His health deteriorates under the weight of his shame, and Chillingworth, suspecting the truth, becomes his physician, secretly tormenting him to feed his thirst for revenge.

As years pass, Pearl grows into a wild and intelligent child, often drawing attention for her unusual behavior. Hester, meanwhile, becomes more respected in the community due to her charitable deeds, though the scarlet letter remains a mark of her past. Desperate to escape their suffering, Hester and Dimmesdale plan to flee to Europe together, but Chillingworth learns of their plans and schemes to stop them.

On the day of a major public gathering, Dimmesdale, overwhelmed by guilt, finally confesses his sin before the entire town. He collapses and dies in Hester’s arms, finding peace at last. Chillingworth, robbed of his revenge, soon withers away and dies as well. Hester and Pearl leave the colony, but years later, Hester returns alone, still wearing the scarlet letter. She continues to counsel and support women in need, and upon her death, she is buried near Dimmesdale, their shared gravestone marked with a single "A."

The Scarlet Letter remains a classic exploration of morality, identity, and the impact of societal judgment. Hawthorne’s novel is widely regarded as one of the greatest works of American literature, offering timeless insights into human nature and redemption.