The Chronicles of Narnia: Prince Caspian

Miraz orders Caspian's assassination because the baby is the rightful heir to the Narnian throne, being the tenth in line from Caspian the Conqueror. As Lord Protector, Miraz seized power after the previous king's death and sees the infant as the ultimate threat to his rule. He cannot allow a legitimate heir to live that could challenge his claim to the throne.

The council later accuses Miraz of being untrustworthy, revealing his treacherous nature from the start.

When Caspian blows the ancient horn in the Shuddering Woods, its magic reaches across dimensions and time to those with a deep bond to Narnia. The horn was enchanted to summon help in times of great need, and it specifically calls the Pevensie siblings who had previously been kings and queens of Narnia. This is why they are pulled from 1942 London back to Narnia.

Doctor Cornelius had previously told Caspian about the horn's significance, hinting at its powerful summoning ability.

The Pevensies discover Cair Paravel in ruins because over a thousand years have passed in Narnia since they last visited. When they ruled as kings and queens, it was the height of Narnia's glory, but after they returned to Earth, centuries of change occurred. During this time, the Telmarines invaded and conquered Narnia, and Miraz eventually took power, letting the legendary castle fall into disrepair.

The Narnians whisper about the old days when talking animals and dryads lived freely, hinting at how much has changed.

Peter leads a daring daylight raid on Miraz's castle because he wants to strike before the Telmarine army grows stronger. However, the mission fails badly because Peter underestimates the enemy's preparation and overestimates his own forces. The Telmarines are well-positioned and repel the attack, resulting in significant Narnian casualties and putting the Pevensies in a desperate position.

Trumpkin warns the Pevensies about Telmarine military strength, but Peter chooses to act anyway.

Aslan returns to Narnia and awakens the dormant magical powers of the land itself. The great trees of the forest come alive, rivers rise to fight, and the ancient spirits of Narnia join the battle on the side of the Narnians. This supernatural intervention turns the tide completely, overwhelming Miraz's forces who have never faced such magical opposition.

The trees and rivers had been silent and still throughout Miraz's reign, waiting for Aslan's return.

Miraz's soldiers turn against him during the battle when they realize he is willing to sacrifice his own men to kill Peter rather than fight honorably. When Miraz tries to use his nephew as a human shield and then attempts to betray an ally to save himself, his troops see his true cowardly and treacherous nature. This moral failing causes them to abandon him, allowing Caspian to defeat him in single combat.

Glozelle had always followed orders without question, but even he begins to doubt Miraz's leadership.

The Pevensies must return to Earth because their adventure in Narnia has reached its natural conclusion. Aslan explains that they were brought back to help restore Narnia and crown Caspian as king, but their own lives are waiting in England. Narnia belongs to the Narnians now, and the siblings have grown enough to accept that their time as rulers is over. Their departure is bittersweet but necessary for both worlds.

Aslan had previously told Lucy that their adventures in Narnia would not last forever, hinting at this farewell.

The Telmarines conquered Narnia centuries ago and established a human-ruled kingdom that suppressed the magical creatures who once lived freely. Telmarines view Narnians as primitive and dangerous, while Narnians resent the human occupation of their homeland. Caspian's coronation marks the beginning of peace between these two peoples, as he bridges their divide by accepting both Narnians and Telmarines as his subjects.

Nikabrik and Trufflehunter's willingness to ally with Caspian shows that Narnians can trust certain humans.

Caspian becomes king by defeating Miraz in single combat and then being recognized as the rightful heir by both Narnians and Telmarines. After Miraz's death, the Telmarine council confirms Caspian's lineage as the true descendant of Caspian the Conqueror. His willingness to spare Miraz's life and his alliance with the Narnians earn him respect from all sides, making him the natural choice to unite the two peoples.

Doctor Cornelius had secretly taught Caspian about his royal ancestry, preparing him for this destiny.

Doctor Cornelius helps Caspian escape because he is loyal to the true royal bloodline and cannot stand by while Miraz commits murder to seize power. Cornelius knows that Caspian is the rightful heir to the throne, and as the boy's tutor, he has a duty to protect him. He uses the hidden passage behind the wardrobe to smuggle Caspian out of the castle, giving him a chance to survive and eventually reclaim his birthright.

Cornelius had been secretly teaching Caspian about Narnia's history and the old kings, hinting at his true allegiance.