Prince Caspian

The second installment in The Chronicles of Narnia. A year after the events of The Lion, the Witch, and the Wardrobe, the four Pevensie siblings are summoned back to Narnia, where a thousand years have passed from the perspective of that world's relative time flow. Narnia has mostly been overrun by the descendants of an exiled group of pirates from Earth called the Telmarines (now ruled by the usurper Miraz), but the rightful heir, his nephew Caspian, has magically summoned Narnian help, receiving it in the form of the Pevensies. Once the Telmarines have been beaten back and Caspian proclaimed king, Peter and Susan are told they are now too old ever to return to Narnia.

Tropes used in Prince Caspian include:

Arbitrary Skepticism : In Prince Caspian, Edmund is the only one to remember that Lucy was right about Narnia in the previous book, while Peter and Susan - who ought to know better - are reluctant to believe her when she says she's seen Aslan.
Badass Beard: The Telmarines. It comes with the pirate territory.
Big Bad: Miraz.
Combat By Champion: Peter versus Miraz.
Cool Gate: "The Door in the Air" -- it leads wherever Aslan wants it to lead.
Decapitated Army: Subverted. Miraz's death doesn't lead to Telmarine surrender - in fact, the lords doctored his murder to look like he's been traitorously killed by Narnians and motivate the Telmarine army to fight.
Fighting for Survival: The various citizens of Narnia who help the Pevensies and Caspian.
Herald: Caspian with Susan's horn
It Was a Gift
Kick Them While They Are Down
Legendary in The Sequel: Played with. Thanks to Narnia Time, the characters and events of The Lion the Witch And The Wardrobe are regarded as legends or even Fairy Tales. The Pevensies' reappearance is compared to what it would be like if King Arthur returned to present-day Britain.
The Masquerade: Old Narnians whom the Telmarines consider fairy tales live in hiding.
My Master, Right Or Wrong: Glozelle.
A Protagonist Shall Lead Them: The Pevensies.
Rage Helm: In the movie, the Telmarine armies.
Reverse Psychology: How Miraz is goaded into accepting Peter's challenge even though it was to his advantage not to duel.
Sacred Hospitality
Spared By the Adaptation: Glozelle.
Secondary Character Title
Sibling Rivalry: Specifically between Susan and Lucy. Susan believes Aslan favors Lucy; Peter takes Susan's side in an important argument because she's older and talking logically, while Lucy's suggestion makes no (visible) sense. The film plays it up even more.
Smug Snake: Miraz, mildly.
The Starscream: Glozelle and Sopespian. The former gets a Heel Face Turn in The Film of the Book.
So What Do We Do Now?: At the beginning of the film, Peter in particular is none too happy to be a young teen dealing with stupid schoolboys again, as opposed to a full-grown man and a king
Sour Supporter: Trumpkin.
Sudden Sequel Death Syndrome: All the Narnians from The Lion the Witch And The Wardrobe are dead... from old age... hundreds of years ago.
Tear Jerker: The Pevensies' sad realization that all their friends from the first book/movie are long gone.
Throwing Down the Gauntlet: Peter issues a formally-worded challenge to Miraz.
Try to Fit That On A Business Card: The aforementioned challenge contains Peter's credentials, juxtaposed with Miraz's more meager ones. And a greeting.
- And then Peter throws in Edmund's laundry list of titles and credentials for good measure, just to rub it in.
Unfriendly Fire: Miraz isn't killed by Peter, just knocked unconscious. A full-scale battle ensues, and a Telmarine Mauve Shirt the king insulted earlier finishes him off.
When Trees Attack
With Due Respect: Inverted: Trumpkin argues strongly against Caspian's plan and then volunteers to do the job he just argued against. He explains to the prince that having given advice, now it's time for him to take orders.