Danger Down Under is a Nancy Drew and Hardy Boys Supermystery crossover novel, published in 1995.[1]
Mick Devlin, an Australian admirer of Nancy Drew's, asks her to help his Aboriginal friend Nellie Mabo, who is trying to locate a missing sacred artifact, a tjuringa board, to return it to her clan. She suspects the proprietors of an opal mine. The Hardy boys join Nancy in Australia, where they find the mystery complicated by a clash over land rights in the Outback and a blood-hungry poacher on the verge of creating a new endangered species.