Two journalists make good use of a brisk, factual style and the growing supply of information and data on such scientific puzzlements as flying saucers, our molten inner earth, the Yeti and the Coelacanth. Describing something of the discovery or evolution of each, something of the present state of knowledge and something of the possible future meaning for man, the chapters make absorbing thumbnail sketches of each mysterious marvel. With rising interest we learn of the reliable people who have seen flying saucers and of the new suppositions about man and possible extra-terrestrial life their observations have lead to. More down to earth is the repot on the work of Haroun Tazieff, whose remarkable films of volcano activity have brought about as much hairbreadth adventure as new information on the hot and quivering mass of magma which periodically breaks through its thin encasement of Earth crust. Most fascinating to this reader were the known details of the abominable and elusive snowman. Though no European has brought back physical reports based on first hand knowledge, photographs have been made of Yeti footprints and Himalayan natives have described the animal as tall, humanoid, covered with long white fur and social. These few of the more outstanding last frontiers of discovery make a vivid panorama for scientific pioneers and for the many laymen who have been checking on their doings of late.