Ivan loves visiting his Great Aunt Polly, who is the best prankster ever, and her dog, Geronimo. One day, Great Aunt Polly shows Ivan how to make invisible ink, which is great fun! Until Ivan spills the ink on himself… and turns invisible! Ivan thinks this is awesome at first — imagine all the pranks he can do! But soon he starts to worry… how long will his invisibility last? And what if he stays invisible forever?