The second volume of the Narnia Chronicles closed with the possibility of Lucy and Edmund -- though not their older siblings -- returning to Narnia. "The Voyage of the Dawn Treader" makes good on that story, with the intrepid pair (plus a whiny cousin) returning on a strange sea voyage.
After the events of "Prince Caspian," Lucy and Edmund are sent off to stay with their obnoxious cousin Eustace. But when they admire a picture of a strange ship, suddenly all three kids are sucked in -- and land on a ship at sea. That ship is the Dawn Treader, and on board is Caspian, King of Narnia. He and his companions, including Reepicheep, the valiant warrior mouse, are searching for seven lost lords of Narnia, and their voyage will take them to the edge of the world. Their adventures include being captured by slave traders, a much-too-close encounter with a dragon, and visits to many enchanted islands, including the place where dreams come true.