Search for Sylvane
Seeing his home world fall to the invasive Rieceh-Ta, Barkley flies to Earth to prevent takeover by the same invaders. Searching for his father, imprisoned by the Rieceh-Ta, Barkley hands off the keys to traveling in space to Bert. He must make certain that proof of Earth's qualification to enter the Common Worlds Congress is recovered from Sylvane, who has been taken prisoner by the Rieceh-Ta. Bert tracks Sylvane to a planet too distant for the Rieceh-Ta to reach. There he learns that Earth has been invaded by a consuming biology brought to Earth by Sylvane's sister. He returns to Earth to try to save the planet.