The Phantom Tollbooth By Norton Juster

The Phantom Tollbooth follows Milo on an extraordinary voyage into such whimsical places as the Land of Expectation, the Doldrums, the Mountains of Ignorance, and the Castle in the Air. Throughout his adventure, Milo meets a cast of bizarre and unexpected characters, including Tock, the watchdog; the Gelatinous Giant; and the Threadbare Excuse, who endlessly mumbles the same thing.

Once home, Milo eagerly anticipates using the Tollbooth again. But will it still be there when he returns from school?