Glowing green and bold as brass, Cara the ghost girl gives Jonathan's life a shake-up! She teaches Jonathan's nasty classmates a lesson with her pranks, and the child-hating caretaker of his apartment building, Mrs Krakenhuber, also gets a taste of Caras ghostly powers. With his new green friend, Jonathan finally gets to have fun again, and the move to Berlin turns out to be not so bad. But then Cara suddenly loses her powers, and Jonathan must do everything he can to help her...