When Georgie (Nigel Hawthorne) accepts an opera invitation from an old friend, Lucia (Geraldine McEwan) decides to tag along.
When Lucia (Geraldine McEwan) is invited to become Tilling's next mayor, she chooses Mrs. Mapp-Flint (Prunella Scales) as mayoress.
Lucia's stock market success prompts her to embark on a program of charitable spending in Tilling; the Mapp-Flints stay at Mallards when their house is flooded.
Lucia (Geraldine McEwan) buys Mallards and renovates the property; Elizabeth Mapp (Prunella Scales) drops all pretense of being pregnant.
Georgie hides from society; the Mapp-Flints begin buying the same gold shares that Lucia bought; Mapp and Lucia both run for a council seat.
Major Benjy Flint quickly moves into Mallards only to be tossed out with his possessions when Miss Mapp finally returns.
Lucia and Georgie move into their new homes in Tilling; Lucia catches Mapp in her kitchen and the two women are washed away by a flood.
While Lucia schemes to avoid meeting an Italian contessa, Georgie comes to her rescue; Lucia and Georgie sell their Riseholme homes.
Miss Mapp objects when Lucia offers her garden for the village fete.
Mrs. Emmeline Lucas leaves her acknowledged social position in Riseholme to summer in the Sussex town of Tilling.