The students in Miss Fox's class lead their school in making choices to help keep the planet healthy, such as turning off lights when leaving a room, taking shorter showers, and using cloth bags instead of plastic ones.
When Miss Fox realizes that her students do not have healthy habits, she teaches them that healthful living is fun and rewarding, which they find to be true on Field Day.
Students in Miss Fox's class have a series of mishaps, all involving a certain visiting author, as they try to earn money for a field trip to Roller Coaster World.