Based on the 1968 film of the same name, Chitty Chitty Bang Bang tells the story of an eccentric inventor named Caractacus Potts who, with the help of his children Jeremy and Jemima, sets about restoring an old race car from a scrap heap. Soon, they discover the car has magical properties including the ability to float and take flight. However, trouble occurs when the evil Baron Bomburst desires the magic car for himself. Along with the delectable Truly Scrumptious, Caractacus and the children head to Vulgaria to rescue Grandpa Potts (who has been kidnapped by the bumbling duo, Boris and Goran) and rid the kingdom of its tyrannical, child-hating rulers. With a fantastical flying car, a heartwarming love story, and whole bunch of teamwork, Chitty Chitty Bang Bang is a fun-filled musical for all the family.
The Junkman/Coggins recounts the last race of the Paragon Panther (“Opening”), which was contested against the Vulgarian Vulture in the 1910 British Grand Prix, but the Panther crashed after Vulgarian spies sabotaged it. Years later, the Panther sits in a junkyard, forgotten by all save the young siblings Jeremy and Jemima Potts, who are enamored with the Junkman’s tales and the car’s history. They are shocked when the Junkman tells them he plans to scrap it, but he promises to save the Panther for them if they can purchase and move it within a few weeks. Truly Scrumptious, daughter of the wealthy Lord Scrumptious, arrives at the junkyard seeking a spare part, but upon finding the truant children, takes them home to their father, the widowed inventor Caractacus. Meanwhile, Vulgarian spies acting under the direction of their leader, autocratic Baron Bomburst, have discovered the location of the Panther and make plans to purchase the car before the children.
Truly arrives at the Potts household, an old windmill, with the children and lectures Caractacus on their improper upbringing before leaving; as he prepares a meal for the children (“You Two”), they tell him about the plans to scrap the Panther and he promises to purchase the car for them. Caractacus’s father, Grampa Potts, recounts the family’s troubles (“Them Three”) and after trying some of his son’s inventions, realizes he has devised a candy that can be played like a flute. The next day, Caractacus goes to Lord Scrumptious’s candy factory to sell the design and raise the money needed for the Panther. Truly helps the Potts family make their sales pitch (“Toot Sweets”), but the demonstration ends in disaster as the musical boiled sweetsunintentionally summon many stray dogs who invade the factory. The Vulgarian spies decide to pass themselves off as locals (“Think Vulgar” / “Act English”) as they realize the patriotic Junkman will never sell the Panther to Vulgarians. Dispirited from the Scrumptious Sweet Factory debacle, Caractacus sings a lullaby to the children (“Hushabye Mountain”) and decides to try selling another invention tomorrow.
In the morning, Caractacus brings another invention, his automatic hair-cutting machine, to a local fair, but the first demonstration again goes awry, as the hapless inventor’s machine shaves the prospective client nearly bald. Caractacus escapes the wrathful client by joining a spirited morris dance group (“Me Ol’ Bamboo”) and the hair-cutting machine is sold instead to a turkey farmer, who plans to use it to pluck and cook his birds, giving Caractacus the money he needs to purchase the Panther. After purchasing the derelict racer and towing it home, Caractacus performs an intensive restoration while Grandpa and the children maintain the household (“Posh!”); after several days, Caractacus emerges from the workshop with the beautifully refurbished car, which they decide to take for a drive with Truly. Collectively, they rename the car Chitty Chitty Bang Bang for the unusual noises made by the engine (“Chitty Chitty Bang Bang”), and the four go for a seaside picnic.
During the picnic, the children confess their love to Truly (“Truly Scrumptious”), who reciprocates and realizes she has feelings for Caractacus as well; distracted by their emotions, the adults fail to notice they have become stranded by the rising tide, but Chitty demonstrates its amphibious capabilities by transforming into a boat (“Chitty Chitty Bang Bang” (nautical reprise)) as the Vulgarians attempt to capture the car and the Potts make a clean escape with Truly. Learning the car is also a boat both infuriates Baron Bomburst and renews his desire to own it. The Vulgarians arrive at the Potts family windmill first, though, and believing mistakenly that Grandpa is responsible for the wonders of Chitty, they hook his hut from an airship, kidnapping him inside. The rest of the family arrive with Truly in time to see them taking off with Grandpa. Speeding in pursuit, Chitty goes over a cliff but in another remarkable display, transforms into an aircraft (“Chitty Takes Flight”) and follows the airship, hut, and Grandpa back to Vulgaria.
Upon his arrival in Vulgaria (“Vulgarian National Anthem”), Grandpa is forced by Baron Bomburst to give the Baron’s car floating and flying capabilities like Chitty, working with other inventors previously kidnapped by the Baron. After learning they have failed for years to accomplish this, Grandpa despairs but is cheered by his fellow prisoners, who see their failures merely as learning experiences (“The Roses of Success”). Chitty arrives shortly afterwards bearing Truly and the three remaining Potts; the Toymaker hustles them into his workshop just as the Childcatcher rushes to their landing site, suspecting the presence of children, who are banned in Vulgaria (“Kiddy-Widdy-Winkies”). As Caractacus learns that to comply, the citizens of Vulgaria have sent their children underground to live in the sewers, the Childcatcher tricks Truly and imprisons Jeremy and Jemima.
While the Baron and Baroness prepare for his birthday party (“Chu-Chi Face”), Caractacus, Truly, and the Toymaker devise a plan to rescue the children and Grandpa; having learned of Vulgaria’s misery, Caractacus and Truly vow to end the Baron’s rule (“Teamwork”). The Baroness’s party plans come to fruition (“The Bombie Samba”) as the Toymaker brings in Truly and Caractacus, disguised as dolls that sing and dance (“Doll on a Music Box” / “Truly Scrumptious” (reprise)), distracting the Baron as the children of Vulgaria rush from the sewers and overpower the Baron’s henchmen. The Potts children and Grandpa are rescued (“Us Two” / “Chitty Prayer”). The Toymaker banishes the Baron and Baroness from Vulgaria and the children from underground are reunited with their families (“Teamwork” (reprise)). Caractacus and Truly declare their love for each other as they fly back to the windmill (“Chitty Flies Home”).