The world of the glass-blowers has its own traditions, it's own language - and its own rules. 'If you marry into glass' Pierre Labbe warns his daughter, 'you will say goodbye to everything familiar, and enter a closed world'. But crashing into this world comes the violence and terror of the French Revolution, against which the family struggles to survive. Years later, Sophie Duval reveals to her long-lost nephew the tragic story of a family of master craftsmen in eighteenth-century France.