Gosalyn loses her memory after being hit by a baseball thrown by Tank Muddlefoot. Gabriel Blackstone finds a jack-in-the-box on the beach and brings it to his antique toy store. He doesn't realize that it's a haunted jack-in-the-box containing a ghost, Paddywhack, who loves to make people miserable. Paddywhack learns of Gos' memory loss and uses it to his advantage by making her believe she is his daughter and the best child prankster in the world. Will Darkwing be able to save his daughter or will Paddywhack finally win?