Capricorn (Cap) Anderson has never watched television. He's never tasted a pizza. Never heard of a wedgie. Since he was little, his only experience has been living on a farm commune and being home-schooled by his hippie grandmother, Rain. But when Rain falls out of a tree while picking plums and has to stay in the hospital, Cap is forced to move in with a guidance counselor and her cranky teen daughter and attend the local middle school.

While Cap knows a lot about tie-dying and Zen Buddhism, no education could prepare him for the politics of public school. Right from the beginning, Cap's weirdness makes him a moving target at Claverage Middle School (dubbed C-Average by the students). He has long, ungroomed hair; wears hemp clothes; and practises tai chi on the lawn. Once Zack Powers, big man on campus, spots Cap, he can't wait to introduce him to the age-old tradition at C-Average: the biggest nerd is nominated for class president—and wins.