Original stories by eight science-fiction writers of remarkably divergent imaginations. If there is any recurring theme, it is that of observation. In different but equally funny ways, Ian Watson's ""The Very Slow Time Machine"" and Robert Sheckley's ""Is That What People Do?"" play with the paradoxical relationship between observer and observed. Bob Shaw's ""Amphitheatre"" takes a more serious approach to the moral problem of detached or non-detached scrutiny. With exuberant but mordant irony, Brian W. Aldiss' ""A Chinese Perspective"" suggests the different sorts of future that might be brought about by Eastern or Western approaches to divining the future. In J. G. Ballard's ""One Afternoon at Utah Beach,"" a deceived husband's surveillance of his wife and her lover is transmuted into a fantasy-re-enactment of D-Day. Other contributions: a fine story by Priest about a young soldier caught up in a war waged with ""sense-gases"" and totalitarian propaganda-methods; a jape by Harry Harrison about an Ireland which has learned to harness her own unique, unlimited energy supply; a tantalizing excerpt from Thomas M. Disch's novel-in-progress about a handful of immortals in a world of immortals. A splendid collection.