Peter, Susan, Edmund and Lucy are suddenly called back to Narnia, and they find that Narnia is suffering under the reign of the cruel King Miraz. The king’s nephew, (and son of the murdered rightful king) Caspian, has learned the truth about Old Narnia and has fled the palace. He discovers a group of Old Narnians in hiding who agree to help Caspian regain his rightful throne and save the remaining Old Narnians from certain death.
The Narnia series is one of my favorites. I think C. S. Lewis has a wonderful writing style that really makes the characters come alive.