When a section of the vault of the Kingsbridge Cathedral collapses Merthin, now an apprentice carpenter, shows his genius by developing a cheaper means of repair than his master.
Da en sektion af Kingsbridge Katedrals hvælvinger kollapser viser Merthin, som nu er tømrerlærling, sine særlige evner, ved at udvikle en billigere måde at reparere end sin mester.