Probably The Magician's Nephew is one of the least known of all seven books, since most people only really know of the books which feature the Pevensie children. The children in this book are Digory and Polly, a young boy and girl who live next door to each other in London. Digory's mother is very ill, and his father is in India for work, so he and his mother have come to London to live with her brother and sister in their home. Digory thinks his Uncle Andrew is straight crazy, and is a little wary of him, and he finds he had good reason to feel this way when one day, he and Polly accidentally get into his upstairs study while exploring a tunnel which runs the length of all the houses.
Uncle Andrew, as it turns out, is a magician. He is convinced he's unlocked the secret to moving between their world and other worlds, but rather than go himself (he's quite old, you see, this sort of thing is really only fit for someone still young), he tricks Polly into being sent from their world, leaving Digory no choice but to go after her (well, really he does have a choice, but he's not a douche, so he goes).
