Milo and Tock travel to Dictionopolis, one of two capital cities of the divided Kingdom of Wisdom, and home to King Azaz the Unabridged.
The text is full of puns and wordplay, such as when Milo unintentionally jumps to Conclusions, an island in Wisdom, thus exploring the literal meanings of idioms.
Attached to the package is a note "For Milo, who has plenty of time".
Warned by an included sign to have his destination in mind, he decides without much thought to go to Dictionopolis, assuming this is a pretend game to be played on the floor of his room.
Milo is soon joining the inhabitants, the Lethargarians, in killing time there, a pastime angrily interrupted by the arrival of Tock, a talking oversize dog with an alarm clock on each side (a "watchdog"), who tells Milo that only by thinking can he get out of the Doldrums.
Head abuzz with unaccustomed thoughts, Milo is soon back on his road, and the watchdog joins him on his journey through Wisdom.