Midway through the 21st century, an integrated global computer network manages much of the world's affairs. A proposed major software upgrade - an artificial intelligence - will give the system an unprecedented degree of independent decision-making, but serious questions are raised in regard to how much control can safely be given to a non-human intelligence. In order to more fully assess the system, a new space-station habitat - a world in miniature - is developed for deployment of the fully operational system, named Spartacus. This mini-world can then be "attacked" in a series of escalating tests to assess the system's responses and capabilities. If Spartacus gets out of hand, the system can be shut down and the station destroyed... unless Spartacus decides to take matters into its own hands and take the fight to Earth.

In 205X, armed forces and conflicts are a thing of the past and people live safe, peaceful lives, all thanks to a cheap, inexhaustible source of energy. One day, something strange is discovered on the moon: an ancient corpse in a spacesuit. The corpse is undeniably human, but it appears to be about 50,000 years old! What does this mean about the history of our species and what effect will this discovery have on current human society?