In this new adventure, Maluquinho is spending the holidays at the home of his grandfather Tônico (Stênio Garcia), an inventor who lives in a small community in the interior of Minas Gerais. His friends Junim (Samuel Brandão), Lucio (Cauã Bernard Souza), Bocão (João Romeu Filho) and Nina (Fernanda Guimarães) are coming to the city to help Maluquinho organize the circus for the centenary of the city. On this trip, they meet Tatá-Mirim, a small flame that ends up making the city believe that they are being invaded by the Capeta. So they end up living many adventures.

The principal character in Helvécio Ratton's delightful film has been adapted from a book and comic created by the Brazilian cartoonist Ziraldo, and tells the tale of a happy-go-lucky 10-year-old child growing up in a city in the 60s.