It all started when a girl named Phoebe skipped a rock across a pond and accidentally hit a unicorn in the face. Improbably, this led to Phoebe being granted one wish, and she used it to make the unicorn, Marigold Heavenly Nostrils, her obligational best friend. But can a vain mythical beast and a nine-year-old daydreamer really forge a connection? Indeed they can, and that's how Phoebe and Her Unicorn unfolds. Over time, Phoebe and Marigold acknowledge that they had been lonely before they met and come to truly appreciate the bond they now share.