Born to Lord Dugfall in Ebrauc, Orwen and her twin Oriel grew up amid a long-running feud between the Dugfall and Colingham families. Orwen, fascinated by her brother's boyish world of fighting and football, was disguised as a boy at age nine and sent to safety with cousins. Catching her reflection in an icy puddle, she recognized herself as a boy for the first time, but was placed in a convent school while Oriel trained as a knight.

Tormented by being unseen, Orwen secretly studied saints who lived as men and eventually summoned a fairy. A shabby green-clad fairy named John Punch arrived, declaring he could neither swap bodies nor cut souls, but agreed to make Orwen a knight in exchange for an unspecified future boon. He carried Orwen to Cow Pond and down through its waters into an air bubble containing a beech tree filled with luminous star-birds, where the silent John Matchstick became his nightly fighting tutor.

For years Orwen trained every night beneath the pond, learning a fairy fighting style suited to his lithe frame, while a fairy double slept in his bed. He received a blue-bladed sword with an acorn pommel. By sixteen, his body had developed female features, and his parents arranged his marriage to William Colingham to end the feud. On his final night of training, John Matchstick refused to take back the sword, gifting it to him.

Returning home before the wedding, Orwen was ambushed by four Colingham men intent on raping him to verify his "virginity." Using his fairy training and his sword, he severely wounded all four. Found by Oriel in the stable, Orwen revealed the truth, declared himself a man, and instructed Oriel that the fairy double in his bed would marry William and preserve the peace. Renaming himself Sir Dinadan, he rode away forever.

On the road, John Punch reappeared and named the fee: Dinadan must kill Merlin, who "knows what he did." Laughing, Dinadan accepted the charge and rode south toward Camelot, intent on living openly as a man and pursuing knighthood.