"A sci fi essential book"--Jacket.

"A Tom Doherty Associates book."

In a world in which Mars and Venus were found to be teeming with life--even human life--Louisia-born Marc Vitrac has been assigned to Jamestown, the U.S.-Commonwealth base on Venus, near the great Venusian city of Kartahown. Set in a countryside swarming with sabertooths and dinosaurs, Jamestown is home to a small band of American and allied scientist-adventurers. But there are flies in this ointment--and not only the Venusian dragonflies, with their yard-wide wings. The biologists studying Venus's life are puzzled by how closely it resembles Earth's. Also, it is 1988: the EastBloc has its own base at Cosmograd, in the highlands to the south, and relations are frosty. Meanwhile, at the western end of the continent, Teesa of the Cloud Mountain People leads her tribe into a conflict with the Neanderthal-like beastmen who have seized her folk's sacred caves. Then an EastBloc shuttle crashes nearby, and the beastmen acquire new knowledge--and AK-47s. Jamestown sends its long-range blimp to rescue the downed EastBloc cosmonauts, little suspecting that the answer to the jungle planet's mysteries may lie there, among tribal conflicts and traces of a power that made Earth's vaunted science seem as primitive as the tribesfolk's blowguns.