Based on the known mystery and investigation novels by Jerónimo Tristante, based in the nineteenth century Madrid. Victor Ros is a bright Metropolitan Police Brigade of Madrid, the first Spanish elite force that employs scientific and deductive techniques. Other characters include Clara Alvear, a young woman from a traditional family who becomes the inspector's love interest. Lola 'La Valenciana' friend of the protagonist who works in a brothel. Don Armando, Ros' godfather and chief. And Roberto Aldanza a wealthy man, educated and ahead of his time.