In The Young Vampire (1920), a London girl is possessed by an extra-dimensional entity which mutates her body and turns her into a living vampire. The Supernatural Assassin (1923) tells the tale of a murderous wraith. Finally, Companions of the Universe (1934) is Rosny's last, great novel, a brilliant scientific romance in which a secret group of physicists attempts to breach the limits of the universe beyond photons, sub-particles and wave-sequences; while at the same time offering an in-depth study of the perversity of human sexual relationships. This is the sixth in a series of seven volumes translated and annotated by Brian Stableford presenting the classic works of J.-H. Rosny Aine, the second most important figure in French science fiction after Jules Verne. Until now, Rosny, a member of the Goncourt literary academy, has best been known to the English-speaking public for his prehistoric thriller, Quest for Fire.