The story opens at a rural fair where a struggling hay-trusser, in a drunken state, auctions his wife and infant child to a passing sailor. Awaking sober the next morning, overwhelmed by remorse, he takes a solemn twenty-one-year vow of total abstinence and sets out on a decades-long search for his lost family. Years later, the wife returns to the town of Casterbridge after the sailor's reported death at sea, accompanied by her now-grown daughter, who remains entirely ignorant of the past transaction.
By this time, the former hay-trusser has completely reinvented himself. Through sheer drive and native force, he has risen to become a wealthy corn-factor and the powerful Mayor of Casterbridge. Desperate to protect his hard-earned reputation and shield the innocent girl from the scandalous truth, he arranges a secret reunion with his former wife, eventually courting and publicly remarrying her. They settle into a respectable domestic life, though the Mayor remains haunted by his past and bound by the remaining years of his strict oath.
As the narrative progresses, the dynamics of the town shift with the arrival of a sharp-witted young Scottish manager, whose modern business methods and personal charm quickly eclipse the older merchant's crude dominance. The young manager's rise introduces deep professional rivalry and personal estrangement, particularly after the Mayor's secret past begins to unravel. Complications deepen with the arrival of a former acquaintance from the Mayor's early days, a woman now wealthy who claims a prior romantic commitment and disrupts the already fragile social peace of the household.
The domestic circle becomes a site of intense psychological pressure as hidden identities, long-buried letters, and shifting loyalties come to light. The Mayor's fierce possessiveness and volatile temper steadily alienate those closest to him, leading to a slow and painful dismantling of his authority. The story moves toward a quiet reckoning, where the weight of past misdeeds finally catches up with the protagonist against the unchanging backdrop of the Wessex landscape.
