Laurel (Hayley Mills) is a willful, stubborn, and bratty 16-year-old living in a house on the chalk cliffs of Sussex in southern England with her imperious class-conscious grandmother, Mrs St. Maugham (Dame Edith Evans).
The selfish grandmother has separated Laurel from her divorced and remarried mother, Olivia (Elizabeth Sellars) because she disapproves of her actions and is determined to raise the girl as her own, telling Laurel that she was abandoned and unloved by her mother.
The other occupant of the house is Maitland (John Mills), a male servant who is privy to a lot of secrets he seems to be keeping to himself.
When Miss Madrigal (Deborah Kerr) is hired to look after Laurel (after the previous six applicants for the job fled after meeting the girl) the troubled child directs all her hostility toward her new governess, convinced that she has a mysterious past since she will talk so little about it.
Tensions are brought to a head when old Judge McWhirrey (Felix Aylmer) drops in for lunch and recalls a case he tried many years before.
Mrs St. Maugham