In the final decade of the 20st Century animals, male and female, in rocket ships landed on their moon. By 2080 AD, they had reached the other planets of their solar system. Almost at once there followed the discovery of hyperdrive through which the speed of light was first obtained and later greatly surpassed. And so, at last, Zootopias began the conquest and colonization of deep space.

United Planets Cruiser C57D, now more than a year out from Zootopia Base was on a special mission to the planetary system of the great main-sequence star Sol. This expedition was led by Captain Judith Laverne Hopps and First officer Nicholas Piberius Wilde. In that system was Earth which once held an advanced technologically sophisticated civilization. Their mission was to explore this world and find out why its civilization ended. This is their story.