When Michael walks through the doors of Catholic school, things can't get much worse. His dad has just made the family move again, and Michael needs a friend. When a girl challenges their teacher in class, Michael thinks he might have found one, and a fellow atheist at that. Only this girl, Lucy, isn't just Catholic ... she wants to be a priest. Lucy introduces Michael to other St. Clare's outcasts, and he officially joins Heretics Anonymous, where he can be an atheist, Lucy can be an outspoken feminist, Avi can be Jewish and gay, Max can wear whatever he wants, and Eden can practice paganism. Michael encourages the Heretics to go from secret society to rebels intent on exposing the school's hypocrisies one stunt at a time. But when Michael takes one mission too far--putting the other Heretics at risk--he must decide whether to fight for his own freedom or rely on faith, whatever that means, in God, his friends, or himself.