The Cotswold village of Riseholme, 1930. Emmeline Lucas, recently widowed, has decided that she needs change. Her role in the forthcoming local Elizabethan fete has been taken by rotund Daisy Quantock, friend and neighbour, and Lucia (as Mrs. Lucas is universally known), feels left out. She decides to rent a Georgian house in the picturesque East Sussex town of Tilling-On-Sea for the duration. Georgie Pillson, her closest friend and confidante, accompanies her to view the house. They motor down to Tilling, meeting the formidable Miss Elizabeth Mapp, owner of "Mallards", which Lucia instantly decides to rent, having fallen in love with both the house and town. After staying the night in a local hostelry, the next day Georgie spies a vacant cottage near "Mallards" and decides to rent it to be with his beloved Lucia.
Returning to Riseholme, Lucia sees that dear Daisy is making more than a little mess with her part of "Queen Elizabeth" in the fete and also her organisational skills in the planning of the event. So she takes over, finally obtaining the plum role as "Good Queen Bess" to great acclaim. As the pageant is to be held during their stay in Tilling, they return briefly to Riseholme, where Lucia makes a great success of the occasion.
Journeying to Tilling for their Summer sojourn, they encounter some of the other inhabitants of the town, including Godiva Plaistow ("dear Diva" as Miss Mapp calls her), "Quaint Irene" Coles (reactionary artist and militant), Reverend Bartlett, who speaks in a Scottish accent, but is really from Birmingham, Mr. and Mrs. Wyse, the couple from whom Georgie is renting his cottage and Major Benjy Flint, ex-army ("India"). All are characters in their own right, and both Georgie and Lucia are entranced. Miss Mapp is slightly miffed to find that the new resident of her home is usurping her position as ruler of Tilling. Steps will have to be taken…….