"There's a feeling about this desert which frankly suggests ... impossible things. That's the only way I can put it." The feeling that Professor Silas Orcutt, an American geologist, refers to early in this story, is one that every reader of this rugged and thrilling science fiction novel will share with him after the very first page. The professor, head of a party of five studying geological formations in the Central Australian desert, thought back on the nightmare of shifting sand and crackling electrical charges that had wrecked the truck in which his party was traveling. He thought, too, of the skeleton of a freshly killed crocodile-found hundreds of miles from the nearest river-and the stench of formic acid that remained around its picked-clean bones. The professor's intrepid little group was prepared to find fossils in the Australian rock strata-but not the living kind that shocked them into believing the impossible of the burnt-out lands of the continent down under. Trapped in a desert valley under the pitiless sun, the five found themselves face to face with six-foot-tall ants and deadly giant mantises: survivors from before the dawn of history.