An ancient, enigmatic alien artifact speeds across the surface of Jupiter's frozen moon Ganymede - untouched by man, indifferent to him. Its ceaseless wandering, its mysterious powers of self-defense and propulsion, its very purpose, all are unknown. The rugged human settlers who are terraforming Ganymede's harsh orb name it Aleph. And, being human, they hunt it - in howling packs armed with laser rifles, flanked by servo-assisted bloodhounds. No weapon has ever scarred Aleph's fluid alabaster hide. No wile has ever slowed it down. No human has ever neared it and lived - no one but the old prospector Matt Bohles and young Manuel Lopez. But soon they will discover that their destinies are intertwined with the maddeningly mysterious Aleph... and with their colony's very survival.

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Sections of this novel appeared in the February and April 1983 issues of Amazing Science Fiction Stories.