The Double Jinx Mystery is the fiftieth volume in the Nancy Drew Mystery Stories series. It was first published in 1973 under the pseudonym Carolyn Keene. The actual author was ghostwriter Harriet Stratemeyer Adams. This volume details the story of a family zoo and aviary, believed to have been jinxed by people out to take their land for high rise development. Nancy Drew and her friends must get to the bottom of the mystery, before they are jinxed themselves.