Although Karl begins with a cataclysm, the near total destruction of Earth by the technologically superior Clordians, her vision of the future is an optimistic one. First Earth's survivors develop new powers of mental ""centering,"" then a kind of protective ""focusing"" power against the rival Clordians and, finally, the ability to project themselves around the galaxy just by concentrating on their chosen location's ""True Relation"" coordinates. And though the story cycle hums with vague echoes of other writers--chiefly Arthur C. Clarke--Karl assimilates so good-naturedly that one can't complain. In fact the last story is nearly a replay of the standard interview with visitors from outer space--one almost expects a command to ""take me to your leader""--but in this case the nearly unrecognizable space travelers are the Earth men and the surprised kids belong to a galaxy they call the ""Flicker Path"" instead of the Milky Way. Karl's favorite heroes are cheeky youngsters: Jalish Dozent who first traveled to the pink and green planets inhabited by thought waves; pre-Clordian archaeologist Velta Akhbar who explains ruefully how her now-revered ability to ""put ideas to work"" caused her nothing but trouble when she was a child. But it's the saga's internal continuity--and the sense of documentary reality extending to a series of explanatory ""footnotes""--which is more satisfying than any single episode.