The Magician's Nephew by C.S. Lewis

The Magician's Nephew by C.S. Lewis was not the first book written in the Chronicles of Narnia, but it was the first that happened in the series' timeline.

It follows the story of two friends, Polly Plummer and Diggory Kirk (who later became the Professor Kirk in The Lion, The Witch, and The Wardrobe). They become friends after Diggory and his mother Mable, who is dying from some unexplained disease, move in with Mable's brother and sister who are both unmarried so that they can more easily care for their sister. (Diggory's father is away in India, at this time, and can't help.) One day, the two friends stumble upon an adventure when Andrew, Diggory's unscrupulous uncle, decides to use them in an experiment traveling between dimensions. They find themselves first in what they called "The Wood Between the Worlds" a sort of between place they compare to the shared attic back home that all the houses in their row of houses share. After this, they find themselves in Charn where they (mainly Diggory) accidentally wake up Jadis, the evil queen who is the cause of so many of Narnia's troubles later. And then, after a mishap at home in London, they, Uncle Andrew, the queen, a horse named Strawberry, and Strawberry's owner Frank, find themselves in a brand new Narnia. Diggory, hoping to find some fruit in this new world that would cure his mother, wants to ask Aslan the Lion for some help. But first, Diggory, having brought Jadis, needs to do something to protect Narnia from her. Overall, the story is lovely, and a great tale that will entertain and cheer both children and adults. The story was first published in 1955.