The descendants of aliens who crash landed on Earth in the 1600's are working to remain hidden from persecution in 1968, while helping a group of researchers from the planet Dacia avoid a secret organization called The Planetary Defense Force and quietly leave Earth. The recently formed Union is expanding the tiny outpost on the moon into a Station to house thousands, causing the crash descendants to reluctantly go into hiding. Members of all of the groups band in cooperation to stop a life form, from off world, from wiping out every animal on the planet; starting with humanity.