In this treatment, Welles would arrive in Mexico, where he would be told (and tell) the tale of Bonita the Bull. From there it would be on to Brazil for the Carnival in Rio, which would be followed by the story of the Jangadeiros, when they arrive at Rio's Harbor.
Welles and a twenty-seven member RKO/Mercury crew to begin shooting Carnaval in early February 1942. After documenting the festivities in both Technicolor and black and white, laboratory tests were done of the Technicolor footage in Argentina. Given the positive results, the black and white crew was assigned to shooting locations around Rio and the Easter festivities in Ouro Preto, in the nearby state of Minas Gerais. The Technicolor crew was assigned to shooting fictional re-enactments of musical activities associated with Carnival preparations and celebrations at the local Cinédia Studios.