The novel revolves around the good boy and the bad girl. The good boy is Ricardo, who works as a translator for the United Nations, while the bad girl's names, like her personalities, are countless. Ricardo met the bad girl in the city of Lima, but after a short period, she disappeared completely, only to reappear ten years later in Paris, where she had become involved in politics. Meetings between them recurred due to the good boy's frequent travels, and they met in various countries, including France, Spain, and Britain. Throughout the pages of "The Bad Girl," the lives of the two characters progress from adolescence to old age, accompanying each other on a forty-year journey where fate insists on bringing them together again, each time in a different place, maintaining an unusual relationship that combines love and the madness of desires. Against the backdrop of this relationship and its wild details, all the events of the twentieth century unfold.