Lady Noroison enters the romance as a ruler under pressure rather than through an account of her childhood or ancestry. Count Alier attacks her territory, burns houses and carries off plunder. Noroison Castle shelters a community that needs help beyond its walls. Among the lady's possessions is a small box of ointment given to her by Morgan the Wise, who says that it can cure disorders of the mind. The remedy belongs to the story's magic, not to a historical medical prescription.

Yvain has meanwhile failed to return to his wife Laudine within the promised year. After her messenger rejects him, he abandons courtly life and wanders in the forest. Noroison and two damsels discover him asleep. One of the women recognises a scar on his face and identifies the celebrated knight. She tells her mistress that restoring him could also help settle the war with Alier. The lady recalls Morgan's remedy, and they return to the nearby castle to fetch it.

Noroison tells the damsel to use the ointment sparingly on Yvain's temples and save the remainder. The maiden returns with clothes and a horse, but her concern for the knight leads her to anoint his whole body until the box is empty. She waits out of sight while he wakes and dresses, then approaches as though she has not seen him before. This allows the bewildered man to accept her help without knowing that she witnessed his earlier condition.

On the journey back, the damsel throws the empty box into the river. She tells Noroison that her horse stumbled and the ointment was accidentally lost. Chrétien's account does not say that the lady uncovers the deception. Noroison is angry at losing so precious a possession, yet she orders the household to continue caring for Yvain. He is washed, shaved, fed and allowed to regain his strength. The expense of the remedy does not end her hospitality.

When Alier returns to burn and plunder, Yvain rides out with the defenders. His attack opens the narrow pass and encourages the others to fight more boldly. Noroison watches from a tower while her people praise the knight's courage. The enemy eventually retreats. Yvain pursues Alier towards the count's own stronghold, catches him before he can escape, and accepts his surrender. He brings the defeated lord back to Noroison rather than deciding the settlement without her.

The lady requires peace, compensation for the losses she can establish, and the rebuilding of destroyed houses. Alier agrees under oath and gives pledges. Her people would welcome Yvain as their lord, and Noroison wishes to reward or marry him, but entreaties cannot keep him there. He leaves before the subsequent rescue of the lion that becomes his companion. Related German, English and Welsh retellings reshape the healing episode; their details should not be treated as one identical account. Noroison remains the lady whose generosity makes Yvain's return to action possible without securing his love.