First published in Issac Asimov's SF Magazine in 1988, expanded into novel form in 1990. SIGNED BY THE AUTHOR.

''Aliens who look very much like human-sized flies visit the Earth and spend most of their time viewing our great works of art and architecture, as well as our natural wonders. They say their purpose is simply to record what they're seeing, but then some of the objects begin to disappear, including a significant part of the city of Munich: the novel dazzlingly skates over much of the thematic material of the previous 20 books, as the eponymous aliens memorize bits of Earth so that the Universe can continue remembering itself, while various human protagonists embody linguistic concerns and dilemmas of perception. Space-opera antics continue en passant'' (John Clute & Peter Nicholls/ENCYCLOPEDIA OF SF).