The merchant tells the story of a Catalan family in the middle ages. Jaume Miravall, skilled tradesman and sort of Barcelona "Godfather" luck, in a largely urban environment, where the fourteenth-century Barcelona will become one more star, in a period that includes the years before and after the great crash of 1348 and the terrible scourge of the black plague. At the same time it features adventure elements, describing the commercial conquest of the Mediterranean, which Jaume Miravall will embark.