Idunn (pronounced "ee-done", in some versions Iduna) is the Norse Aesir goddess of spring and eternal youth. She acts as the keeper of enchanted apples that retain her fellow gods' eternal youthfulness.
Magnus encounters a pigeon that tells him Samirah al-Abbas, Blitzen, and Hearthstone that he knows how to get the Sword of Summer, but he wants something in return: Idunn's apple of immortality. To get the apple, they will need to attract the sea goddess, Ran.
- Her name is traditionally spelled Iðunn.
- She is similar to the Greek Goddess of youth, Hebe.
- Idunn Mons, a mons of the planet Venus, is named after Idunn.
- Idunn's apples do not prevent death during Ragnarok.
- But they are still delicious and never out of season.
- The Swedish magazine Idun was named after the goddess; she appears with her basket of apples on its banner.