Lucy fears that she has been away from the Professor's house for hours and hours, but when she rejoins her brother and sisters, they are confused by her anxiety, because no time at all has passed while she has been in Narnia. Lucy tells them about the magic wardrobe and the forest, and describes the wintry scene that she encountered in Narnia, but when they look in the wardrobe again, they see nothing out of the ordinary. The others pound on the back of the wardrobe, but find nothing. Lucy insists that she is telling the truth, but Peter suggests that she stop making things up. Her siblings worry aloud that Lucy is crazy, and Lucy begins cry. Peter and Susan think that her behavior is particularly strange, because she has always been a truthful girl, but Edmund takes this opportunity to sneer at his sister. The days pass: Lucy remains downcast, and is unable to properly enjoy the good weather and play out-of-doors with her siblings. Peter and Susan continue to worry. Lucy thinks to herself that she will wait for another rainy day to return to the wardrobe, and figure out once and for all whether Narnia is real.
When another rainy day comes, the children decide to play hide-and-seek. Susan is "it". Lucy takes this opportunity to peek into the wardrobe once again, to determine whether Narnia is really there, or if it was, in fact, only a dream. She isn't planning on hiding in the wardrobe, but she hears footsteps, and impulsively leaps inside.
The footsteps belong to Edmund, who sees Lucy dart into the wardrobe. He follows her and shuts the door behind him, "forgetting what a very foolish thing this is to do." Inside the wardrobe, he sees a light, and, believing that the door has somehow opened, moves towards it.
Suddenly, Edmund finds himself in a forest. The sky is bright blue, and it is winter. He calls out to Lucy, but she doesn't answer. Edmund decides that she is ignoring him because she is still mad, and is hiding or off "sulking somewhere." Suddenly, he hears the sound of jingling bells. A sledge pulled by two white reindeer, with a fat dwarf behind the reins, comes to a stop in front of him. In the sledge, Edmund sees the tallest lady he has ever seen in his life. She wears a white fur coat and a gold crown, and carries a long, gold wand. Her face is as white as snow, with a very red mouth: her countenance is beautiful, but her expression is "proud and cold and stern." The lady asks Edmund who and what he is, and Edmund replies that he is "Edmund". The lady introduces herself as the Queen of Narnia.
In this chapter, an essential difference between Narnia and the "real world" is revealed: the two places have different timelines. While Lucy feels as though she has been away for hours and hours, she emerges from the wardrobe to discover that no time at all has passed: life picks up just where she has left it. When the children gather around the wardrobe to prove Lucy's story, however, they find that it is quite ordinary. The point of entry is not a constant, and certain conditions must be met in order for the door into Narnia to open. Lucy's initial discovery suggests that the wardrobe can only be transformed into a doorway by someone who is pure and innocent, and is not intent on proving or disproving the existence of Narnia.
When Lucy tells her siblings about Narnia, she is upset by the fact that they do not believe her. Though she is a truthful girl, the others are convinced that she has made up the whole thing. In this scene, Edmund reveals his unpleasant personality when he sneers at his sister and makes fun of her. Over time, the skepticism of her siblings causes Lucy to begin to doubt the authenticity of the experience herself.
On the next rainy day, Lucy decides to look into the wardrobe again to determine whether or not Narnia was a dream. The sound of Edmund's footsteps, however, causes her to leap into the wardrobe. The narrative implies that she enters the wardrobe with the requisite feeling of innocence, not out of a desire to prove or disprove the existence of Narnia. Presumably, had Lucy entered the wardrobe with the express desire to address her siblings' skepticism, the door would not have opened for her.
Edmund follows Lucy with the intention of teasing his sister, not out of a desire to prove or disprove the existence of Narnia. Therefore, Edmund also exhibits the requisite, child-like sense of "innocence." Edmund is also the second-youngest of the siblings, and the narrative - quite logically - allows him to progress into Narnia next. It is also important, however, to note that Lewis draws particular attention to the fact that Lucy and Edmund are polar opposites. He specifies that Lucy is careful not to shut the wardrobe door behind her, but emphasizes Edmund's carelessness and lack of foresight by specifying that he shuts the door when he enters the wardrobe.
Once in Narnia, Lucy disappears, and Edmund finds himself standing alone in the woods on a winter's day. Once again, Lewis draws the reader's attention to the differences between Lucy and Edmund: Lucy believes in the inherent goodness of everyone whom she encounters, while Edmund focuses on the negative. When he realizes that Lucy is missing, Edmund immediately leaps to the conclusion that his sister is angry with him and "sulking somewhere." Clearly, Lewis wishes to indicate that Edmund is a poor judge of character.
When Edmund arrives at the same lamp-post that his sister encountered earlier, he meets not Mr. Tumnus, but the White Witch herself, suggesting the divergent paths that Lucy and Edmund are about to embark upon.