Sarah Burton returns to her childhood home after many years away to apply for the new vacant position of headmistress at the local school. Her personality wins over many people, but at least one of the school governors, Robert Carne, is against her appointment for reasons at first unclear. He is a landowner who recently lost the vote to become the new MP there, but Robert has his own troubles with a wife in a mental home and a daughter that has started to show signs of mental instability. He is just one of many people that Sarah Burton will encounter in the poverty stricken area of South Riding.

Sarah checks out her new school and teachers ready for the term to come, but is less than impressed by both the conditions of the building and the staff's lack approach to teaching. She also checks out the other pupils that will be attending there when she goes to a local stage production, where she encounters the Holly family, a family of nine who live in caravan type slums and who one of their daughter is rushed in to hospital with suspected appendicitis. The eldest daughter Lydia befriends the new neighbours Fred and Nancy Mitchell, who have had to move there when money became tight. While Nancy is snobbish about the area, Fred encourages Lydia's love for literature.

Sarah has her first meeting with Joe Astell, newly elected Alderman of the area at the local Jumble Sale and discovers they are like minds on many things. Anthony Snaith has hopes that his plan for the new road and development will go through, despite opposition from some locals, including former Alderman Robert Carne. But he has troubles of his own with his wife in a mental home and costs spiraling and things take a turn for the worst at the local hunt. Meanwhile councillor and vicar Alfred Huggins' sins come back to haunt him when Bessie Warbuckle has a startling revelation for him.

Sarah Burton is determined to secure improvements for her school building as term time begins and attracts the notice of councillor and vicar Alfred Huggins in her bid to gain funding. Pupil Lydia Holly is also gaining notice, especially for her school work, which rises hopes for Sarah as a possible promising pupil, but a sudden turn of events at home threatens those prospects. And a harsh winter for 1932 devastates much of the community, including local squire farmer Robert Carne, who Sarah finally meets properly when she is on hand to help when one of his cows goes into labour.

It's Easter 1933 now, and squire Robert Carne is reduced to selling the family heirlooms to make ends meet as his farming business continues to struggle. Sarah discovers why Lydia Holly's schoolwork has deteriorated when she learns that her mother has died and she is now having to raise her siblings. Determined to do something for a girl with promise she lobbies Mrs Beddows into doing something, but she is in for a surprise. Tom Sawdon, landlord of The Nag's Head, has bought his wife Lily and Alsatian dog to keep her company but she struggles to cope with it and goes to extreme methods in her way to get rid of it. And there is worse to come for South Riding when an outbreak of measles hits the community.