The Fifth Civilization has been discovered. They are living proof that humans and aliens share the same ancestry. Five years after first contact, however, the Fifth Civilization is in danger.



The militaristic Kotaran race rules much of the planet with an iron fist. And the Quad Company, a cartel made up of the four technologically advanced races, strip mines the land to extract its resources. Abuses and killings are rampant. Amidst this hostile atmosphere, the Earth Minister of Universal Rights, Kazumi Koda, arrives on this distant world to investigate the Quad Company. She also seeks the alien scientist David, a champion of the rights of the Fifth Civilization, who vanished months ago while visiting this planet.



Faced with obstruction at every turn, Kazumi heads north on a riverboat into the wild interior of this world. She hopes to find David there, and maybe even the human Nick Roan, long since presumed dead. But the journey is perilous. Kazumi is met with Quad Company threats, dangerous wildlife, and hostile tribes. A shadowy conspiracy is also afoot, monitoring Kazumi in hopes she leads them to David. For David may know why travel to the planet’s half-destroyed moon, Ultima Meridian, has been forbidden. On Ultima Meridian, the rumors go, one can uncover the secret of every civilization’s lineage.