In The Phantom Tollbooth by Susan Nanus, Milo opens a package to find a tollbooth and a car.
Milo is then transported to the Doldrums where nothing ever happens and meets Tock the watch dog and the legarthians.
After that Milo and Tock go to Dictionopolis where they meet the Spelling Bee, and the Humbug. They find out Rhyme and Reason where banished and the kingdom needed them back.
Thank you for rescuing princesses Rhyme and Reason!
Milo met King Azaz of Dictionopolis, and the Mathmagician who is king of Digitopolis and they have Milo, Tock and the Humbug go rescue the princesses. The kings give them a box of letters and a magic pencil to help them.
Milo, Tock and the Humbug used their gifts to fight the demons and rescue the princesses from the castle on air.
The kings helped them fight off the demons and were thankful for Milo, Tock, and the Humbug for bringing rhyme and reason back to the kingdom. Then Milo had to leave and was never bored after that.