In the book Miraz is already king and only targets Caspian to secure his son's claim on the throne, having previously been content with Caspian as his heir.
Miraz's attempted assassination of Caspian is likewise different. In the film he finds out much later, and is prompted to try and take revenge for it. We find out that Miraz murdered Caspian's father earlier in the book, and it's a cause for Nightmare Fuel - so that Caspian knows what his uncle is capable of. She's also seen fighting alongside the guys in just about every battle sequence.
Here, she becomes a total Action Girl, killing the enemies with arrows just by throwing them and holding off a group of soldiers alone with her bow and quiver of arrows. She was given the moniker "The Gentle" for a reason, and had a very passive role in the book.
NARNIA 2 MOVIE FREE
Goes from a minor spirit asking Aslan to free him from the Telmarine bridge to a powerful water deity that drowns the Telmarine army and swallows Lord Sopespian. Peter and Caspian likewise have a rivalry that isn't in the book. In the film, both Peter and Susan have been affected badly - Peter getting into fights and Susan becoming anti-social. In the book, none of the Pevensies seemed too affected by abruptly leaving Narnia and becoming children again, after having ruled as kings and queens for over a decade and all but forgetting their old lives.
Adaptational Angst Upgrade: In spades. Miraz in the book was a traditional evil yet cowardly monarch, whereas in the film he is cold-blooded, calculating, and seems unafraid of anything. Trumpkin is more cynical and snarky than his book counterpart. In the book the horn was blown much later, with all of Caspian's supporters present, and Trumpkin was specifically sent to Cair Paravel, as it was predicted that the help would likely arrive there. However in the film Trumpkin was not immediately present when the horn was blown, as he charged off to fight the soldiers pursuing Caspian, and was not present for the explanation of the horn's power either. Adaptation-Induced Plot Hole: Like in the book, Trumpkin still deduces right away that the four children who save him from drowning are the ancient monarchs of Narnia, summoned to help by Queen Susan's magic horn. The Narnia saga is still on the rails, but over the next five movies, I fear a continual replaying of the fantasy-theological contest between good and evil, before the arrival of Lewis's Book of Revelations, The Last Battle, is going to get a little wearing. It's a long shot of her stunned face, quite different from the untroubled children in the group, a shot that Adamson does not immediately replace with what she is looking at in the way we might expect. This second episode certainly has much of the first film's ingenuous openness and energy, and that is very largely due to another scene-stealing performance from Georgie Henley as Lucy, who, in being able to see Aslan before anyone else, is in a state of grace exceeding her siblings the scene in which she does so is rather daringly executed. Well, there are no easy answers to these questions, and we must instead contemplate the usual fantasy-movie staples: there's the gigantic medieval field of battle and also, worryingly, the boring convocation scene in which grey-bearded lords and elders debate their strategic intentions for our benefit. Through it all, three questions dominate: where is Aslan now when will he, or rather He, make His Second Coming and why, oh why, has He not made It before now? A mighty battle commences, along with a lethal temptation by the forces of darkness, triggering a resplendent cameo for Tilda Swinton as the wicked White Witch. The children's reign is a distant folk memory, and Narnia with its gentle woodfolk creatures has been overrun by human invaders, the Telmarines, whose evil King Miraz (Sergio Castellitto) is preparing to fortify his reign by executing his nephew Caspian, a decent sort who believes in friendship with the Narnians. Just as the children are chafing at their reduced non-royal status, they find themselves taken back to Narnia, but they have been catapulted 1300 years into the future, during which time there has been precious little advance in technology: there are crossbows, and that's about it. We know the date from a glimpsed newspaper: July 12 1941, at the time of the British-Soviet pact strategic alliances are, of course, to be important in Narnia's parallel universe, too. Our famous four, Peter (William Moseley), Susan (Anna Popplewell), Edmund (Skandar Keynes) and Lucy (Georgie Henley) are down in the Strand tube station in wartime London. Prince Caspian begins with a brilliant narrative flourish.