'Quinn, Willow, Krystal and Ellabeth are Unicorn Riders – empowered to protect the land of Avamay. Head Rider, Willow, must confront her past when the Unicorn Riders are summoned to the town of Arlen. Her Uncle Gildenfair, who Willow hasn’t spoken too for many years, is ill and needs a healing elixir that only the Riders can provide. When Arlen is besieged by a neighbouring Lord’s army, the Riders and their unicorns must help the townspeople defend the city. Can Willow find the courage to forgive her uncle for past wrongs and help him save Arlen? ' (Publication summary)