Cathedral of the Sea follows the fortunes of the Estanyol family, from their peasant roots to a son, Arnau, who flees the land only to realize spectacular wealth and devastating problems. During Arnau�s lifetime Barcelona becomes a city of light and darkness, dominated by the construction of the city�s great pride�the cathedral of Santa Maria del Mar - and by its shame, the deadly Inquisition. As a young man, Arnau joins the powerful guild of stone-workers and helps to build the church with his own hands, while his best friend and adopted brother Joan studies to become a priest. When Arnau, who secretly loves a forbidden Jewish woman named Mar, is betrayed and hauled before the Inquisitor, he finds himself faceto-face with his own brother. Will he lose his life just as his beloved Cathedral of the Sea is finally completed?