The English siblings, legendary Kings and Queens of Narnia, are magically recalled, once again children, by the refugee Prince Caspian.
Peter, Susan, Edmund and Lucy Pevensie are magically whisked away from a British railway station to a beach near an old and ruined castle.
They discover the treasure vault where Peter's sword and shield, Susan's bow and arrows, and Lucy's dagger and bottle of magical cordial are stored.
Susan's horn for summoning help is missing, as she left it in the woods the day they returned to England after their prior visit to Narnia.
Caspian escaped from Miraz's castle with the aid of his tutor Doctor Cornelius, who schooled him in the lore of Old Narnia, and gave him Queen Susan's horn.
During a midnight council, Doctor Cornelius arrived to warn them of the approach of King Miraz and his army; he urged them to flee to Aslan's How in the great woods near Cair Paravel.
After one volunteer disappears through the magic door created by Aslan, the Pevensies go through to reassure the other Telmarines, though Peter and Susan reveal to Edmund and Lucy that they are too old to return to Narnia.
The two major themes of the story are courage and chivalry and, as Lewis himself said in a letter to an American girl, "the restoration of the true religion after a corruption".
The second in the series of films from Walt Disney Pictures and Walden Media, titled The Chronicles of Narnia: Prince Caspian, was released in the US on 16 May 2008.