Their brief encounter produces a son and later leads to their reunion.
Dunstan crosses the wall, meets Una, kisses her in exchange for a glass snowdrop, and spends the night with her.
Their sibling connection links the royal succession plot to the hero's ancestry.
Septimus recognizes Una at the witches' castle as his long-lost sister.
Una's royal birth makes her part of the King's family.
Una is revealed to be Septimus's long-lost sister, while Septimus is one of the King's sons.
Una protects Yvaine before the witches capture them both.
Una notices Yvaine approaching the wall and intervenes by taking control of Sal's caravan to stop her.
Una is imprisoned because of her attempt to protect Yvaine.
Lamia captures Una together with Yvaine and takes both of them to the witches' manor.
Explore the full interactive character relationship map of Stardust