Young Lucy, Edmund and their cousin cross through a painting into a magical land where they sail with King Caspian to help Narnian lords banished by an evil usurper of the throne.
Upon returning to Narnia to join Prince Caspian for a voyage on the majestic royal vessel known as "The Dawn Treader," Lucy, Edmund, and their cousin Eustace encounter merfolk, dragons, dwarves, and a wandering band of lost warriors. As the edge of the world draws near, their remarkable adventure at sea sails toward an exciting, yet uncertain, conclusion.