One day, Francisco Javier Balmis, the well-known doctor appointed by Carlos IV to undertake an expedition to eradicate smallpox in South America, arrives at the orphanage run by Isabel Cendal. Balmis has with him a number of children to carry the vaccine and suggests that Isabel travel with him, in addition to a young surgeon, José Salvany. Together they begin the long journey, replete with anecdotes, which will change all their lives forever and reveal new geographic and emotional terrains to them. De Arteaga’s new novel is set in the early 19th century, when Spain is beginning to receive Enlightenment ideas from France. With wonderfully moving characters, the author of La princesa de Eboli (The Princess of Eboli) and La Beltraneja takes a highly important historical event and creates from it a plot involving love and adventure.