Aspiring architect Norton Juster became interested in how people perceive their environment. He got a grant from the Ford Foundation to write a book on urban planning. Partway through the project, he realized the work wasn’t leading in the direction he’d hoped. Exhausted, he took a break. A chance encounter in a restaurant—with a kid who wanted to know what the biggest possible number was—got Juster thinking about his own childhood questions. He began to sketch out the story that became The Phantom Tollbooth.

A neighbor, artist Jules Feiffer, took an interest in the children’s story and agreed to illustrate it. An editor read a partial draft and got Juster a contract to finish the book for publication. The urban planning book never was completed.

Milo is bored. Nothing seems important to him, his school lessons least of all. He heads home to his eighth-floor apartment, goes to his room, sits, and stares at his unused toys.

Milo notices something new—a very large package in one corner. Attached is a blue envelope addressed, “FOR MILO, WHO HAS PLENTY OF TIME” (12). It’s not his birthday or a holiday, and he hasn’t been especially good. He opens the envelope anyway.