Anna wants nothing more than to be helpful to her older sister, and Queen of Arendelle, Elsa. However, as far as Anna can see, ever since her sister's coronation, Elsa has been doing just fine without her.

But when a mysterious sickness strikes Arenedelle, Anna sees the perfect opportunity to finally help. Following the discovery of a secret room within the castle, Anna incants a magical spell, hoping it will make her dream of curing the sickness come true. Instead, a more sinister dream comes to life ...