Fifteen-year old Antonia Cunningham is on a seemingly impossible mission: to solve the hundred-year-old mystery of the true identity of the Clown Prince of Crime, with only the assistance of her rag-tag team which includes a cranky, crime-obsessed classmate, an anti-social Biology whiz kid and a mysterious informant who goes by the alias "Ace". The clock is ticking as the Joker slowly worms his way into Antonia's subconscious, putting her own sanity on the line. Because madness, as you all know, is like gravity...