Peter and Susan are still playing hide-and-seek, but eventually Edmund and Lucy find them. Lucy bursts out with her news: her story is true, Narnia is real, and Edmund has been there, too!
Edmund lies and says that he and Lucy were just playing, pretending that her country in the wardrobe was real, but it was all make-believe.
Lucy, crushed, runs out of the room.
Edmund tries to act superior, but Peter tells him to shut up and stop egging Lucy on.
Edmund says that it's all nonsense, and Peter says that's the problem – he's worried that Lucy is going crazy, and thinks that Edmund is making it worse.
Susan makes peace between Peter and Edmund. All three of them go and find Lucy, who has obviously been crying.
Lucy sticks to her story. After all, it's the truth. All evening, Lucy is miserable, Edmund is uncomfortable, and Peter and Susan worry that their little sister is losing her mind.
The next morning, Peter and Susan go to the Professor. (Remember him – the kind old man who owns the big country house the children are staying in?) They sit in the Professor's study and tell him the whole story.
The Professor listens without interrupting. At the end of the story, he asks how they know that Lucy's story isn't true.
Susan is taken aback. She mentions that Edmund said they were only pretending, and the Professor asks whether Edmund or Lucy is usually more truthful. Peter says that, until now, Lucy was always more reliable.
Susan suggests that Lucy could be mad, but the Professor says that she's obviously sane.
Finally, the Professor puts the case to Peter and Susan logically: either Lucy is telling lies, or crazy, or telling the truth. She's never told lies before, and she's obviously not crazy, so they have to assume that she's telling the truth.
Peter asks how Lucy's story could possibly be real. He thinks that real things are always there, and clearly sometimes the wardrobe isn't a doorway to another world. The Professor isn't so sure of this.
Susan mentions the time discrepancy – the way Lucy said she had been gone for hours, while only a few moments passed for everyone else. The Professor says this supports her story: if there is another world, time works differently there, but that's not the kind of thing that a little girl making up a story would think about and fake.
Finally Susan asks what they should do, and the Professor says that everyone should mind their own business. With that, the conversation is over.
For a while, things go on as usual, and none of the children mention Narnia to each other.
The narrator explains to us that the Professor's house is famous, mentioned in guidebooks, and sightseers often come to see it. When they do, the housekeeper, Mrs. Macready, shows them around. Mrs. Macready dislikes the children, and they are supposed to stay out of the way when she's giving tours.
One day, the children are examining an old suit of armor when they hear Mrs. Macready and some visitors coming toward them. They quickly move to another room, but, no matter where they go, the tourists seem to be right behind them. Eventually, they find themselves in the spare room, and all four of them are forced to hide in the wardrobe!