The Magician's Nephew: The Chronicles of Narnia

Digory and Polly meet and become friends one cold, wet summer in London. Their lives burst into adventure when Digory's Uncle Andrew, who thinks he is a magician, sends them hurtling to...somewhere else. They find their way to Narnia, newborn from the Lion's song, and encounter the evil sorceress Jadis, before they finally return home.

This was the sixth book written in The Chronicles of Narnia. It now stands as the first book in the series.