The Mohole Mystery is a juvenile science fiction novel, the eleventh in Hugh Walters' Chris Godfrey of U.N.E.X.A. series. It was published in the UK by Faber in 1968, in the US by Criterion Books in 1969 under the title The Mohole Menace. It was also published in French as Pionniers des ténèbres, (literally "Pioneers of Darkness") by Éditions de l'Amitié in 1973 and as A ameaça de Mohole in Portuguese by Edições Dêagã.