Mary Smith arrives in the small, rural town of Cranford to stay with two spinster sisters, Deborah and Matty Jenkyns. Deborah is the dominating force in Cranford society, and the kind-hearted and eccentric Matty believes her to be the best judge in all matters. The Jenkyns are intrigued when Captain Brown, his daughter Jessie, and Jessie's ailing older sister move into the house across the street.
A handsome new doctor, Frank Harrison, also comes to Cranford. A young bachelor trained in London, Dr. Harrison becomes the talk of the town, not only for his revolutionary medical methods, but also for the effect he has on many female hearts. He soon sets his sights on Sophy Hutton, the rector's oldest daughter.
Ten-year-old Harry Gregson is caught poaching by Mr. Carter, the trusted estate manager of Lady Ludlow, Cranford's reigning aristocrat. However, Mr. Carter is so moved by Harry's dismal poverty, good nature, and intelligence that he offers to secretly teach him to read and write.
At Lady Ludlow's garden party, the ladies are scandalized by the news that a new railway line is to be built running straight through Cranford. Is this the end of Cranford?