Set in the 1910s, the story opens with Jeremy and Jemima Potts, who live with their widowed father Caractacus Potts, an eccentric inventor, and his equally peculiar father. While skipping school, they meet Truly Scrumptious, a beautiful upper-class woman with her own motorcar, who brings them home to report their truancy to their father. Truly shows interest in Caractacus' odd inventions, but he is affronted by her attempts to tell him that his children should be in school.