The utopian society of Mars has thrived in underground cities for over ten thousand years. The Martians have lived peacefully and tranquilly, tending their underground growing fields of fruits and vegetables. All their lives change when the Intergalactic Traders, ruthless killers, threaten to conquer and enslave the planet. They have a spy and murderer roaming the underground tunnels that connect the cities. Two Martians, Mango, a scientist and poet, and his daughter, Kimberline, an engineer, must save the planet from destruction. A third danger lurks in the Martian population. A strange genetic disease kills most Martians before they are twenty-five years old. Kimberline's daughter, eight year old Beauti-Anne, has the dreaded disease and will die if something isn't done.