The Story in Brief
Digory Kirke and Polly Plummer are London children who stumble into the study of Digory's uncle — a vain, reckless amateur magician — and are transported via magic rings through the Wood Between the Worlds, a quiet place of pools that each lead to a different reality. They visit Charn, a dead world whose last queen they accidentally wake, and witness the very birth of Narnia as Aslan sings it into existence. It is Lewis's creation myth, written after The Lion, the Witch and the Wardrobe had already made Narnia famous. Greta Gerwig's Netflix adaptation is the first of a planned new series.
Key Differences
Lewis's narrative voice
Lewis writes directly at the reader — confiding, digressive, occasionally stern — in a way that gives the novel an intimacy no film can replicate. He addresses children as intelligent people deserving of honest storytelling, and that relationship between narrator and reader is the book's secret engine. The film must find other ways to establish trust with its audience.
The creation sequence
Aslan singing Narnia into existence is one of the most quietly extraordinary passages in children's literature. It works precisely because it happens in your imagination, guided by Lewis's prose. Gerwig's visual realisation of this scene will inevitably be spectacular — but a Narnia you can see is a different experience from a Narnia you construct yourself from the words on the page.
Jadis's role
In the novel, the White Witch is a terrifying presence but ultimately a supporting character — the story belongs to Digory and Polly. Gerwig is reportedly expanding Jadis's role significantly in the first film, which makes commercial sense but shifts the story's centre of gravity away from the children and toward the villain.
Digory's grief
The emotional engine of the novel is Digory's dying mother and his desperate hope that Narnia might offer a cure. Lewis handles this with directness — the grief is real, the temptation is real, and the resolution is genuinely moving. The film is expected to foreground this more explicitly, which risks sentimentalising what Lewis keeps restrained.
Uncle Andrew
Lewis's Uncle Andrew is a precise comic portrait of a certain kind of self-important man who considers himself above ordinary moral rules. He is funny and pathetic in equal measure. How much of that satirical precision survives the translation to a film aimed at a broad family audience remains to be seen.
Should You Read First?
Absolutely — The Magician's Nephew is a short book you can read in a few hours, and Lewis's creation sequence deserves to live in your imagination before Gerwig's version replaces it. Read it first. Then see what she does with it.
Gerwig is the right director for this material — her ability to make the familiar strange is exactly what Narnia needs. But Lewis's novel is short enough that there's no excuse not to read it first. Do so, let the creation sequence happen in your head, and then go watch Gerwig make it her own.