In a small town in the south of England, Mrs Tavistock nostalgically evokes a tragic episode from the past. She reads the letters written to her aunt Madeleine by her from the fiancé, a young medical student and member of the International Brigades who disappeared on the Aragon front in the spring of 1938. At the same time, in Barcelona, Alfred finds his reasonably happy life upset by the suicide of his father, a solitary, embittered old man to whom he had not spoken for years. The discovery of a package of papers hidden in the family home and a series of very strange phenomena lead him to investigate the dark seeds of silence that have for years stifled his family's daily life. Los llavors del silencio moves in almost detective mode through the past and present of two families scarred by the war, and reflects on identity, guilt and what is left behind.