The Chronicles of Narnia - The Voyage of Dawn Treader (C.S. Lewis)

A year in the Pevensie world and exactly three years in Narnia.

King Caspian X was actually ruling Narnia in a fairly peaceful way but The Voyage of Dawn Treader didn't take place in the magical country, but in the sea.

This tells the adventure of King Caspian upon his search of the ten Lords of Narnia whom his evil uncle Miraz banished while he ruled the country. Caspian was doing this in fulfillment of his promise to Aslan in the previous book.

The Pevensie kids who returned to Narnia during this adventure were only Edmund and Lucy for Peter was studying for an exam with Professor Diggory Kirke and Susan has gone to America for her studies. In short, the two were already old enough to go back to Narnia.

Lucy and Edmund weren't the only ones who came back, but they were accompanied by a rather reluctant cousin of theirs, Eustace Clarence Scrubb. Now that name would be too important for the last two books of Narnia for the Pevensies wouldn't be returning anymore because probably by that time, Edmund and Lucy have already both outgrown their age and like Susan and Peter, would be too old to go back to Narnia anymore.

The Dawn Treader's journey in search for the banished Narnian Lords was so much of an adventure and it was really fun to read until the last chapter. Every island that they will step into would hold magic or an uncommon experience that not all of them could forget.

Even the "evil" Eustace was able to appreciate the beauty of the lands held by Narnia and how powerful Aslan is.