Plot

During the Battle of Britain, in the suburb of Finchley near London, Great Britain, the Pevensie children, Peter (William Moseley), Susan (Anna Popplewell), Edmund (Skandar Keynes) and Lucy (Georgie Henley), are endangered by an attack of numerous German Heinkel He 111 bombers.

The next day, Mrs. Pevensie (Judy McIntosh) herds her four children, Peter, Susan (Anna Popplewell), Edmund, and Lucy (Georgie Henley), onto an evacuation train at Paddington Station, the London terminus of the Great Western Railway. Mrs. Pevensie lovingly pins identification tags on each one and exhorts the older ones to take care of the younger ones. The four children ride out of London to a town called Coombe Halt, where the first motorcar they see simply blares its horn at them and moves on, leaving them standing there wondering whether, in Edmund's words, they might have been incorrectly labeled.

Just then a horse-drawn cart appears, driven by a severe-looking middle-aged woman whom Peter guesses is the "Mrs. Macready" whom they were told to expect. Mrs. Macready is housekeeper to Professor Digory Kirke, who lives on a vast estate dominated by a large house containing a wealth of historical artifacts from classical times and the Middle Ages.

They are evacuated to the country home of Professor Digory Kirke (Jim Broadbent), who is not accustomed to having children in his house, as Ms. Macready (Elizabeth Hawthorne), the strict housekeeper, explains. The house is so like a museum that the children are subject to some rather strict rules

The children's first day on the estate reveals the tensions among the siblings. Edmund Pevensie is, quite simply, a "rotten kid", Lucy is homesick, Peter feels the weight of trying to be the Man of the Family while their father is fighting the war, and Susan is constantly "trying to be smart" and thus often bumps heads with Peter.

While the Pevensies are getting used to the house and playing hide-and-seek out of boredom, Lucy discovers a wardrobe. Lucy climbs inside and burrows in among the coats, but then finds that she can keep going, deeper and deeper, until she emerges into a snow-covered woodland called Narnia to her surprise. Strangest of all the objects she sees is a perfectly functioning gas lamppost standing far away from any sort of street.

Lucy shortly encounters and befriends the faun (half man and half goat), Mr. Tumnus (James McAvoy), who explains about the land she has just entered. Tumnus is delighted to learn that Lucy is a human and invites her back to his home for tea, which she accepts. There, he puts Lucy asleep by playing a Narnian Lullaby on his flute. He plays a hypnotic tune on a flute-like instrument, and Lucy actually sees shapes form in the flames of Tumnus' hearth fire, shapes of a man riding a unicorn, and fauns and Dryads dancing. Eventually Lucy drops her teacup and falls asleep, and then another shape entirely forms in the flames: an angry lion who roars at Tumnus, stopping his playing and snuffing out the candles in his home.

However, when she wakes up, Lucy finds Tumnus grieving, and he explains that Jadis (Tilda Swinton, the White Witch, has cursed Narnia, and it has been winter for one hundred years and ever Christmas. If a human is ever encountered, they were to be brought to her. Tumnus takes a huge liking to Lucy and cannot bring himself to kidnap her, so he sends her home. When she returns, hardly any time has passed in the normal world, and her siblings do not believe her story since when they look in the wardrobe, it has a normal wooden back.

That night, Edmund follows Lucy into the wardrobe. However, he enters Narnia as well, and shortly after searching for Lucy, he is nearly run over by a sleigh drawn by six large white reindeer stags. He meets the White Witch who claims to be "The Queen of Narnia" and her dwarf Ginarrbrik. She regards Edmund at first with stern aspect and considers him a trespasser. But when she learns that he is one of four siblings, her attitude changes. She smiles, beguilingly, and offers him a seat in her sleigh.

She offers him Turkish Delight as well as the prospect of becoming king and having power over his siblings if he brings them to her house. After she departs, Edmund and Lucy meet again and return. Edmund doesn't tell Lucy about his meeting with the White Witch.

Lucy tells Peter and Susan about the experience, but Edmund spitefully betrays her by pretending that Lucy had simply imagined it. The Professor talks with Peter and Susan, as he does not understand why they do not believe Lucy's story. The others know she is neither mad nor dishonest, so Lucy must be telling the truth.

While running away from Ms. Macready after accidentally breaking a window while playing cricket, the four siblings retreat to the wardrobe and enter Narnia. Peter chastises Edmund for lying about Lucy and forces him to apologize to her. Then the four, wearing oversized coats taken from the wardrobe, set off for Tumnus' house, at Lucy's suggestion.

They discover Mr. Tumnus has been taken by the Witch's secret police. Tumnus' house is a total wreck, with smashed furniture and crockery, piles of blown-in snow, and a crudely lettered parchment containing a notice accusing Tumnus of high treason. It is signed with the paw-print of a wolf, and the name Maugrim, identified as "captain of the secret police."

They meet Mr. (Ray Winstone) and Mrs. Beaver (Dawn French), who tell them about Aslan (Liam Neeson). According to the beavers, Aslan is on the move to take control of Narnia from the Witch. The four must help Aslan and his supporters as it has been prophesied that if two sons of Adam and two daughters of Eve sit in the four thrones, the White Witch's reign would end. The beavers shocked them further by saying that "Aslan" has outfitted an army for them to lead. Mr. Beaver explains the witch's motive and that the siblings now must resort to reaching Aslan to save him.

Edmund sneaks off to visit the Witch. The others try to follow but arrive only in time to see Edmund entering a very large, forbidding palace, seemingly constructed of ice and stone. Peter tries to follow, but the male beaver stops him, saying that Edmund is the bait for a trap. When Edmund arrives at her castle, the White Witch is angry that he did not deliver his siblings. Now sounding not very beguiling at all, but talking clearly for the first time, she frightens him into revealing that his brother and sisters are in the beavers' house. Edmund is locked up in a prison cell.

The Witch sends wolves to hunt down the children and the beavers, who barely escape with the help of a fox. At the house, the beavers hurriedly packed some supplies, and then the three children and two beavers escape into a tunnel just as Maugrim and his pack invaded the house. The five emerge into another clearing, where they find the stone statue of a badger, which the two beavers recognize as once a buddy of the male beaver's. The fox (Rupert Everett) who offers to hide them up a tree while he sends Maugrim and his pack off on a fool's errand.

Edmund is chained in the Witch's dungeon where he meets Tumnus. She demands to know where they went and is on the point of striking him with her upraised scepter when Edmund abruptly drops the name of "Aslan." Tumnus is shocked to hear him reveal so much. The Witch demands that Edmund reveal where Aslan is. Edmund hesitates when Tumnus claims that Edmund does not know anything, and Edmund tells the Witch that he heard no further information regarding Aslan. Seeing that Tumnus is hindering the information, the Witch tells Mr. Tumnus that Edmund betrayed him (by talking about him at Edmund's first visit), then turns Tumnus to stone. Every one of those statues is not a statue at all, but a petrified victim of the Queen of Narnia.

While Peter, Lucy, Susan and the beavers travel to the Stone Table, they see what they believe to be the White Witch chasing after them, so they hide. It is really Father Christmas (James Cosmo), a sign that the Witch's reign is ending. Father Christmas gives Lucy a healing cordial (That can heal any injury) and a dagger to defend herself with. Susan, a bow and arrows and a magical horn that will summon help when blown, and Peter a sword and shield.

Pursued by wolves led by Maugrim (Michael Madsen) captain of the White Witch's secret police, the group crosses a thawing river, leaving the Witch unable to reach them. The Witch's wolves who then appear had captured the fox that helped the Pevensies escape. The Witch then demands that the fox reveals the Pevensies destination.

After the fox refuses to comply, the Witch is about to turn him to stone when Edmund reveals that the Pevensies are heading to the Stone Table and that Aslan is already assembling his army. Arriving at Aslan's camp, the group encounters Aslan, who is revealed to be a huge & noble lion. Aslan promises to help Edmund in any way he can. Later, Peter, now dressed in the leather jerkin of a Medieval officer, talks frankly with Aslan about the battle to come, and about Peter's future career as High King of Narnia, a post that he will have to win in combat.

Two wolves ambush Lucy and Susan while they are frolicking by the river. Susan manages to blow her horn to summon help. When Peter intervenes, Maugrim attacks him. Aslan arrives and restrains the other wolf. Behind Aslan come several galloping centaurs, led by Oreius (Patrick Kake), who draws his sword. Aslan tells them to stay where they are and let Peter fight his battle. Peter kills Maugrim with his sword. After some of Aslan's troops follow the other wolf to the witch's camp and rescue Edmund, Peter is knighted by Aslan. The next morning, Aslan talks to Edmund alone about what he has done, and then re-introduces Edmund to his siblings, telling them "There is no need to speak about what is past."

After Edmund and his siblings reunite, The White Witch journeys to Aslan's camp and asserts her claim to the traitor Edmund. Edmund must surrender himself to her, to be executed on the Stone Table--otherwise, Narnia will be destroyed completely. Aslan secretly offers to sacrifice himself instead. That night, as Lucy and Susan covertly watch, Aslan is killed by the White Witch at the Stone Table with a crowd of creatures watching.

Jadis orders her own chief general, a Minotaur named Otmin (Shane Rangi), to prepare for battle. Lucy opens her bottle of fire-flower cordial, but Susan says that it is too late for that, because Aslan is dead. The cordial is a potion, and Aslan can no longer swallow it. Edmund encourages Peter to take command. Edmund reminds him that Aslan believed in him. In the morning, both armies clash in battle. Peter deploys a cavalry consisting of centaurs and leopards at the base of a cliff, and orders Edmund to command the rest of his forces, armed with bows and arrows, at the top of the cliff. Peter even has an air force, consisting of talking eagles, falcons, hawks, and Gryphons. He designates some to act as fighters, some as bombers, and some as aerial scouts.

Aslan is resurrected, citing magic beyond the Witch's understanding (a willing victim who has committed no treachery dies in a traitor's stead, the Stone Table will crack, and death itself will turn backwards), and takes Susan and Lucy to the Witch's castle to free the petrified prisoners that the White Witch turned to stone, forming reinforcements for Aslan's army.

Edmund persuades Peter to lead Aslan's army to fight the White Witch's forces. Though Aslan's army begins to have a winning streak, the White Witch's huge army is much larger than Aslan's (aka Peter's), so it soon begins losing. To stop the Witch from attacking and killing Peter, Edmund attacks the White Witch and destroys her wand but is fatally wounded by the Witch in return. Peter, angered at what the Witch did, fights her. Aslan arrives with reinforcements and kills her. While Susan kills Ginarrbrik (when he attempted to kill Edmund), Edmund is healed by Lucy's cordial. The Pevensies are crowned King Peter the Magnificent, Queen Susan the Gentle, King Edmund the Just, and Queen Lucy the Valiant.

Fifteen years later, while chasing a white stag through the forest, they come to the same forest clearing where the lamppost is. Lucy begins to remember, and with Edmund, Susan and Peter following, fights through the trees, where they begin to tumble through the coats and finally out of the wardrobe and return to England, becoming children again. The Professor enters the room and asks what they were doing. Peter says he wouldn't believe them, and he responds, "Try me."

Lucy later attempts to return to Narnia via the wardrobe, but the Professor tells her he has been trying for years, and they will probably return to Narnia when they least expect to return.