Harry Potter and the Sorcerer's Stone

An eleven-year-old living in a cupboard under the stairs is informed by a very large man that he is a wizard, and that there is a school. The first half is the pleasure of being shown around — a bank run by goblins, a train from a platform that isn't there, a hat that sorts children into houses by looking inside their heads. The second half is a mystery about what is being guarded on the third floor.

What holds it up is that the school is a real school. There is homework, an unfair teacher, a sport everyone cares about too much, and a rival who is mostly just a snob. The magic is treated as a subject you can be bad at. That ordinariness is why it works on children who have no interest in fantasy at all.

It is the shortest and lightest book in the series by a distance, and the plot is a straightforward detective story with a twist about who to suspect. Read now it is hard to see past everything that came after it, but the first hundred pages still do the one thing the whole thing was built on: they make an ordinary child's life sound like a door had been shut on him.