Lucy (Georgie Henley) and Edmund (Skandar Keynes) Pevensie return to Narnia with their cousin Eustace (Will Poulter) where they meet up with Prince Caspian (Ben Barnes) for a trip across the sea aboard the royal ship The Dawn Treader. Along the way they encounter dragons, dwarves, merfolk, and a band of lost warriors before reaching the edge of the world.