At a rural English garage, two children, Jeremy and Jemima Potts, find a car formerly used for racing in Grand Prix in Europe until it crashed and burned in 1909. When they learn the car is due to be scrapped, they beg their widowed father, inventor Caractacus, to save it; he makes lots of unsuccessful attempts to sell his inventions to raise money to buy it, until he earns tips from a song-and-dance act at a carnival. He purchases the car and rebuilds it with a new name, “Chitty Chitty Bang Bang” for the unusual noise of its engine. In the first trip in the car, Caractacus and the children picnic on the beach with a wealthy woman with whom they have previously had awkward encounters, Truly Scrumptious. Caractacus tells them a tale about nasty Baron Bomburst, the tyrant of fictional Vulgaria, who wants to steal Chitty Chitty Bang Bang. The story starts with the quartet escaping Bomburst’s pirates. The Baron then sends two spies to capture the car, but they capture Truly’s father, Lord Scrumptious, then Caractacus’ father, Grandpa Potts by accident, mistaking each for the car’s creator. Caractacus, Truly, and the children see their Grandpa Potts, being taken away by airship, following it to Vulgaria, which involves the car sprouting wings and propellers to fly. Grandpa is taken to the castle and has been ordered by the Baron to make another floating car just for him. He bluffs his abilities to the Baron to avoid being executed. The Potts’ party is helped and hidden by the local Toymaker, who now works only for the childish Baron. Chitty is discovered and then taken to the castle. While Caractacus and the Toymaker search for Grandpa and Truly searches for food, the children are kidnapped by the Baroness’s Child Catcher, as children are against the law in Vulgaria under Bomburst’s rule. The Toymaker takes Truly and Caractacus to a grotto beneath the castle where the townspeople have been hiding their children. They concoct a scheme to free the children and the village from the Baron. The Toymaker sneaks them into the castle disguised as life-size dolls for the Baron’s birthday. Caractacus snares the Baron, and the children swarm into the banquet hall, overcoming the Baron’s palace guards and guests. In the ensuing chaos, the Baron, Baroness, and the evil Child Catcher are captured. Jeremy and Jemima are freed by Caractacus and Truly and fight against the guards. Chitty comes to their rescue, and, at the same time, they are reunited with Grandpa. The Potts family and Truly bid farewell to the Toymaker and the rest of the village, then fly back home to England. When Caractacus finishes the story, they set off for home, stopping to drop Truly off at Scrumptious Manor, where Caractacus dismisses any possibility of them having a future together, with what she regards as inverted snobbery. The Potts family arrive back at their cottage where Lord Scrumptious surprises Caractacus with an offer to buy one of his inventions, the Toot Sweets, as a canine confection, re-naming them Woof Sweets. Caractacus, realizing that he will be rich, rushes to tell Truly the news. They kiss, and Truly agrees to marry him. As they drive home, he acknowledges the importance of pragmatism as the car takes off into the air again, this time without wings.
