Arnau Estanyol arrives in Barcelona and joins the powerful guild of stone-workers building the magnificent cathedral of Santa Maria del Mar, while his adoptive brother Joan studies to become a priest. As Arnau prospers, he secretly falls in love with a forbidden woman. When he is betrayed and hauled before the Inquisitor, he finds himself face-to-face with his own brother. Will he lose his life just as his beloved cathedral is finally completed, or will his brother spare him'.