The main character Roy Eberhardt moves to Florida and into the town of Coconut Cove where his classmate Dana Matherson starts to bully him. On the bus to school, Roy sees a boy running barefoot outside. Roy tries to leave the bus, but Dana chokes and strangles him. He escapes after punching Dana in the face, breaking his nose, and then exiting the bus. But Roy can't catch the running boy because a golf ball hits Roy in the head. The school suspends him from the bus for two weeks and orders Roy to write an apology to Dana. Roy calls for a truce, but Dana refuses.
A restaurant called Mother Paula's All-American Pancake House decides to build a franchise in Coconut Cove, but vandalism delays the work. Roy learns the running boy is the vandal known as "Mullet Fingers", and they become friends. Mullet Fingers vandalizes and delays construction to save an endangered species—the burrowing owl—that live on the site.
The construction foreman, named Leroy "Curly" Branitt, denies the owls' existence. Roy helps Mullet Fingers prove otherwise and tells his class about the owls, how construction will kill the endangered species, and encourages them to join him in protests. Roy and his classmates attend the ground breaking and expose the truth. This includes the company's illegal removal of an environmental impact statement from their files. This revelation saves the owls and their habitat. Mother Paula's All-American Pancake House blames former employees and promises to preserve the property as an owl sanctuary.
Mullet Fingers's mother sees him protesting with Roy and his classmates and takes her son home. Two days later, Mullet Fingers climbs out his home's bathroom window and is mistaken for a burglar. Mullet Fingers's mother lies to the police and says he stole a ring. They believe her, and he's sent to a juvenile detention center where he escapes. In the last chapter Roy discovers that Mullet Fingers's real name is Napoleon Bridger.