A Thunder on Neptune

In a post-holocaust future, one of the founders of the system-spanning Combine is spending a large fraction of mankind's resources to investigate the changes occurring on Neptune. Having failed in his first attempt at sending direct investigators five years ago, he is now enlisting precocious children, from whose viewpoints the story is told. Readers of any age will find these characters difficult to believe in, let alone identify with, and several will recognize that Gordon ( Falling Towards Forever ) has taken his main plot from a combination of Clarke's 2010 and a story in Simak's City series. The alien Kith are on stage much too briefly for us to understand them or the reasons for their actions. (Dec.)