Caleb is a ten-year-old boy in Sutton, Indiana, who longs for an extraordinary life. Unhappy with his father's insistence on being an ordinary family, he actively seeks adventure and uniqueness. His desire to stand out makes him eager to bend rules and begin a complex series of trades.

Styx is a sixteen-year-old boy in the foster care system who recently moved to the area. Confident and smooth-talking, he carries a business card claiming he is an "Anything Man." He introduces the Franklin brothers to the concept of the Great Escalator Trade and represents the ultimate freedom Caleb craves.

Bobby Gene is Caleb's eleven-year-old brother. Named after his father, he often acts as the voice of caution and attempts to temper his brother's impulsive decisions. Despite his affinity for following their parents' rules, he remains loyal to Caleb and frequently joins his misadventures.

Dad is a strict, protective father who places a high value on his family blending in as ordinary folks. He actively limits his children's travel outside of Sutton to protect them from perceived dangers in the wider world. His conservative approach to parenting causes friction with Caleb's desire for excitement.

Mom works the afternoon shift at the local hospital. She strictly enforces household rules and quickly issues extra chores as punishment when the boys misbehave. She is highly protective of her children and develops a wariness toward their older new friend.

Cory is an eleven-year-old neighborhood boy initially seen as a bully. He desires a baby sibling so much that he temporarily trades his illegal fireworks just to hold Susie. He eventually joins Caleb and Bobby Gene in their daily garden chores.

Susie is the one-year-old sister of Caleb and Bobby Gene. Her innocent involvement in a poorly planned trade sets off the boys' initial punishment and their subsequent need to hide a sack of fireworks.

Mrs. Cormier is Cory's mother. She coordinates with Mom to issue a joint punishment of extra garden chores for the boys after the fireworks incident.

Pixie is a young white girl who lives in the same foster home as Styx. She chooses her nickname to match Styx's name and occasionally joins the boys on their trips to the woods.

Robo is a man who maintains a collection of scrap and used car parts. He serves as the first successful trading partner in Styx's Escalator Trade plan.

Mr. Maddox is a local farmer who owns a broken riding lawn mower. Styx approaches him to trade the spare car parts they acquired from the junkyard.

Mr. Davis is the owner of the local hardware store. He displays a shiny green moped in his window, which becomes the ultimate prize the boys seek to obtain through their trades.

Mr. Pike is an older man who lives in a dilapidated house surrounded by spare parts and junk. The boys encounter him during a risky train ride when they attempt to acquire a motor for the broken lawn mower.

Uncle Greg is Cory's uncle. He rides a Harley-Davidson motorcycle and is preparing to welcome a new baby into his family.