The Lion, the Witch and the Wardrobe, completed by the end of March 1949[13] and published by Geoffrey Bles in London on 16 October 1950, tells the story of four ordinary children: Peter, Susan, Edmund, and Lucy Pevensie. They discover a wardrobe in Professor Digory Kirke's house that leads to the magical land of Narnia. The Pevensie children help Aslan, a talking lion, save Narnia from the evil White Witch, who has reigned over the land of Narnia for a century of perpetual winter. The children become kings and queens of this new-found land and establish the Golden Age of Narnia, leaving a legacy to be rediscovered in later books.

The story begins in 1940 during World War II, when four siblings--Peter, Susan, Edmund, and Lucy Pevensie--are evacuated from London to escape the Blitz. They are sent to live with Professor Digory Kirke, who lives in a country house in the English countryside. While the four children are exploring the house, Lucy looks into a wardrobe and discovers a portal to a magical world named Narnia. There she meets a faun named Tumnus. He invites her to tea in his home. There he confesses he planned to report her to the tyrannical White Witch but has thought better of it. Upon returning to our world, Lucy's siblings do not believe her story about Narnia. Her spiteful older brother Edmund enters the wardrobe and meets the White Witch, who befriends him and offers him magical Turkish delight that enchants him. She encourages him to bring his siblings to her in Narnia, with the promise that he shall rule over them. Edmund joins Lucy in Narnia and then returns with her to the Professor's house. But after returning he lies to Peter and Susan: he denies Lucy's claim that Narnia lies behind the wardrobe. Eventually all four of the children enter Narnia together while hiding in the wardrobe. They meet Mr. and Mrs. Beaver, who invite them to dinner. The beavers recount a prophecy that the witch's power will fail when two Sons of Adam and two Daughters of Eve fill the four thrones at Cair Paravel. The beavers tell of the true king of Narnia, a great lion named Aslan who has been absent for many years but is now "on the move again." Edmund sneaks away to the White Witch. Her castle is filled with stone statues--enemies she has petrified. The beavers realize where Edmund has gone and abandon their home, leading the children to Aslan. As they travel, they notice that the snow is melting, indicating that the White Witch's spell is breaking. A visit by Father Christmas confirms this. The children and the Beavers meet with Aslan and his army. Peter engages in his first battle, killing a wolf who threatens Susan. The Witch approaches to speak with Aslan, insisting that according to "deep magic from the dawn of time" she has the right to execute Edmund as a traitor. Aslan speaks with her privately and persuades her to renounce her claim on Edmund's life. That evening, Aslan secretly leaves the camp, but is followed by Lucy and Susan. Aslan has bargained to exchange his own life for Edmund's. The Witch ties Aslan to the Stone Table and then kills him with a knife. The following morning Aslan is restored to life. Unknown to the witch, "deeper magic from before the dawn of time" allows someone who willingly dies in the place of another to return to life. Aslan allows Lucy and Susan to ride on his back as he hurries to the Witch's castle. There he breathes upon the statues, restoring them to life. Peter and Edmund lead the Narnian army in a battle against the White Witch's army but are losing. Aslan arrives with the former statues as reinforcements. The Narnians rout the evil army, and Aslan kills the Witch. The Pevensie children are named kings and queens of Narnia. Several years later, now adults and mounted on horseback, the siblings go hunting for a White Stag. Just beyond the lamppost, branches become coats. The siblings are back in the wardrobe and are children again. They reenter the Professor's house.

Four school children have left there home to go to a "safe haven" during the war. Here they find a magical portal to the distant land of Narnia, where the White Witch rules and it's always winter, yet never Christmas. Will the children be able to save Narnia? Will Aslan come and help them?