A mill-owner's ambitious daughter almost ruins her husband's political career.

On 7 May, 1945, at the end of World War II, George Boswell, the mayor of Browdley, an impoverished mill town in England, remembers the last twenty-six years of his life: As an enthusiastic city councillor and newspaper editor, George champions the appointment of Olivia Channing to the post of assistant librarian, even though the town has long condemned Olivia father's John for closing down his mills and plunging the people into desperate poverty. Impressed by George's defense of her, Olivia contrives to bring him to her isolated, hilltop mansion, Stoneclough. There George meets the sick and lonely John, whose only friend is the town's doctor, Richard Whiteside. Although the reform-minded George is ambiguous in his feelings about John, his attraction to Olivia and her unconventional ways quickly grows. One day, a distraught Olivia confides in George that she is in danger of losing Stoneclough because of unpaid bills. Later, as George is walking Olivia home during a raging storm, he proposes marriage, but receives no answer. After George leaves her at Stoneclough, Olivia has a violent argument with her father, who then catches a ride to town with Richard. On the way down the hillside, Richard's car crashes over an enbankment where the road has washed out, and John is killed. When George rushes to Stoneclough with the news, Olivia is already grieving and suddenly accepts George's proposal. During their London honeymoon, George meets with Wetherall, Browdley's representative in Parliament, who, along with Olivia, encourages George's political ambitions. Three years later, Olivia and George are living in town with their son Martin when Richard, who has slipped into alcoholism, gives George a paper he has written about health conditions in the overcrowded houses of Browdley. When George shows Richard's paper to influential businessman Trevor Mengin, who has interests in three Browdley mills, Mengin dismisses the report as too negative. Later, Wetherall tells Olivia that he is retiring from Parliament, but feels that George is still too inexperienced to take his place. Despite Wetherall's apprehensions, George accepts Mengin's offer to stand for Wetherall's seat and begins a campaign calling for social reform, but backed by Mengin's business interests. During the campaign, however, a diphtheria epidemic breaks out because of the unsanitary conditions in the slum housing, and Richard demands that the city council open a free clinic. Later George insists that Olivia have Martin immunized at the clinic, but she becomes impatient there and leaves without getting the shot. The epidemic and George's realization that Mengin has been manipulating him cause the councilman to drop out of the race. The ambitious Olivia is outraged by George's decision, declaring that she has no special concern for the poor's children, only her own. Then, Martin falls ill with diphtheria and dies. Overwhelmed with grief and disappointment, Olivia divorces George and goes to Switzerland. Many years later, after George has been elected Browdley's mayor, the Channing mills suddenly reopen, and George discovers that Olivia has returned with Charles Winslow, her grown son from her second marriage, who is on a brief leave from the military. When a worker is seriously hurt at a Channing mill, George reluctantly visits the widowed Olivia at Stoneclough to discuss safety conditions, but she persists in her attitude of social indifference. Just then, however, Olivia learns that Charles was shot down during battle and is recuperating at a nearby hospital. Although the sight of Charles' scarred face horrifies Olivia, she dedicates herself to his recovery and, over the next months, becomes obsessed with caring for him. In particular, the domineering Olivia objects to Charles' romance with Richard's adopted daughter Julie and pressures him to leave the hospital, where Julie works as an aide, and move in with her. When Charles, who has already obtained a marriage license with Julie, gives in to his mother, Julie is devastated. As George and Richard are about to celebrate the end of the war, they learn of Julie's plight, and Richard finally reveals to his friend his suspicion that, after she quarreled with her father about marrying George, whom John wanted to protect from his conniving daughter, Olivia allowed him to drive in the storm, even though she knew about the washed-out road. At Stoneclough, George then confronts Charles and accuses him of cowardice. George's words cause Charles to leave home to marry Julie that night, and George happily tells Olivia that her manipulations have failed. Finally free from Olivia's grasp, George joins his fellow townspeople in celebrating the war's end.