In THe Phantom Toolbooth by: Susan Nanus a boy named Milo passes through a toolbooth to another land called Dictionopolis.
Along the way to Dictionopolis Milo meets a dog named Tock in the Doldrums and he decides to join Milo. Tock tells Milo that Dictionopolis and a land called Digitopolis have been chaos since the kings banished the 2 princesses who created peace.
When Milo gets to Dictionopolis, he meets King Azaz who wants him to help save the princesses along with Tock, and a lying bug named Humbug. But Milo needs permission of both kings, so he travels to Digitopolis and The Mathemagician (king) at first doesn't want Milo to go but gets tricked and allows Milo to go.
Milo, Tock and Humbug start traveling to the Castle in the Air which is where the princesses got banished. Along the way they meet scary demons who try to stop them. For example the Terrible Trivium forces them to do useless tasks.
Finally Milo, Humbug and Tock get to the castle in the air with many demons chasing them. They quickly move to the top floor and rescue the princesses, but since the demons are in the castle, Tock has to fly them down. Eventually the demons stop chasing them.
Milo, Tock, and Humbug saved the princesses and soon it's time for Milo to leave. He says his goodbyes and drives back home as the kings start fighting again. He comes home and thinks he has been gone for a while, but it's only been an hour. Sometimes time flies, but sometimes it takes a while. THE END!