The Pnume

His exploration ship blasted from orbit, Terran scout Adam Reith is stranded on Tschai, a world colonized by three alien species -- the Chasch, the Dirdir, and the Wannek -- while the planet's original inhabitants, the mysterious Pnume, lurk underground. In the fourth and final book of the cycle, Reith's plans to leave Tschai are foiled by the treachery of Aila Woudiver, who delivers him into the clutches of the subterranean-dwelling Pnume. Reith escapes, and teaming with a young and reluct...