"The Voyage of the Dawn Treader" is a sequel to "Prince Caspian", taking place a few years after the events in the prior book. It is structured around a sea voyage of young King Caspian to the easternmost reaches of his realm.

Once again, magic pulls Edmund and Lucy into the world of Narnia, though this time their older siblings Peter and Susan are absent (having become too old for Narnia, it seems). Instead, they are joined by their cousin Eustace, a thoroughly disagreeable character, who will undergo a major change during this book.

The journey of the ship "Dawn Treader" to a group of islands in the East advances the plot. On each island, the companions encounter new dangers and temptations, be it slave traders, a greedy dragon or a well containing secret and evil magic. As they progress, they also find traces of the seven Narnian lords who traveled to the islands in the time of Miraz, who had usurped the throne during Caspian's youth.

Another quest is that of Reepicheep, the corageous mouse, who follows a prophecy made at his birth that he would reach the true East and find Aslan's country. And indeed, he will eventually find the edge of the world... and Aslan, of course.

While "The Voyage of the Dawn Treader" contains memorable scenes, such as the attack of a giant sea serpent on the ship, or the description of the eerie Island of Dreams, it feels rather slight compared to the earlier novels. It mainly serves as a transitional book between the early and the late titles in the Chronicles of Narnia.