By Norton Juster
A bored boy drives a toy car through a magic tollbooth into a land where words and numbers have gone to war, and sets out to rescue two banished princesses and put it right.
Milo is bored by everything — school, home, the whole business of being awake. One afternoon a tollbooth turns up in his bedroom for no reason he can explain, so he drives his little electric car through it, mostly because he can't think of anything better to do. On the other side is the Lands Beyond. He picks up a watchdog named Tock, who has a real clock in his side and actually ticks, and a pompous beetle called the Humbug, and the three of them go off to rescue two princesses, Rhyme and Reason, who were banished for settling an argument. Getting there means passing through Dictionopolis, where words are sold at a market and you can eat them, and Digitopolis, where numbers are dug out of a mine, and finally out-thinking a mountain full of demons who'd rather he never made it home.
The whole book runs on wordplay — puns, idioms taken literally, jokes that only work if you already know the word being played with. A child who reads well above grade level tends to love that, because the book treats getting the joke as the reward. There's nothing older tucked inside: no romance, no real violence, nothing dark. It's a witty, brainy adventure that assumes the child reading it is clever and lets them prove it. Milo also starts out sure that everything is dull and slowly stops believing it, which some children take to heart, though the book never stops to spell the lesson out.