Description: While working for the United States geodetic survey, paleontologist Bruce Dayton meets with a half-mad individual by the name of Eugene Scott, who has lived for years in a hidden cave. The old man has chosen this hermit existence to devote himself to the study of evolution. He claims to know how to send a mind back through the ageseven to the first forms of lifeand asks young Dayton's permission to dispatch him upon that amazing journey. The young man humors the old fellow and, in a fever, falls asleep. In a bewildering daze, Dayton suddenly finds himself living in the trees as an australopithecine named Aka, the Sentinel. So begins his wild journey through humanity's dawn, inventing tools, battling cave bears, surviving conflicts between titanic sea monsters, and challenging his tribe's brutish chief. As his adventure continues, Dayton begins to wonder: Can he can hold on to his human mind while living the life of an animal, or will his last vestiges of reason and imagination smother under the instincts of the ape? The story begins: Was it a dream, that vision of the old Kansas Sea that boiled and roared in awful grandeur over our Mississippi Basin so many thousands of centuries ago?