 Raph, a Gurrow archaeologist, learns of the arrival on the continent's eastern seaboard of an unknown race, apparently descended from chimpanzees, who resemble 'Primate Primeval', the extinct race whose existence he has been trying to prove.Their science is more advanced and they are more war-like.It is implied that the arrivals may try to invade and colonise the lands occupied by Gurrows, and that they have developed nuclear weapons.