William Halloway and James Nightshade are two boys who live in the small Midwestern town of Green Town, Illinois. Born a few days apart, and just short of their fourteenth birthdays, the two boys live next door to each other and are inseparable best friends. A mysterious lightning rod salesman comes through town and strikes up a conversation with the boys, warning them that a storm is approaching. The boys learn that a carnival is coming to town called Cooger & Dark's Pandemonium Shadow Show; they see ads in the stores downtown.

Charles Halloway is Will's father. He is fifty-four-years-old, and feels old and unhappy. He is the janitor in the town's public library, which is also his favorite refuge, especially late at night when no one else is there. Charles also sees the posters for the carnival and feels nostalgic for his youth.

Train whistles awaken...