the EDF from total destruction by finishing off Dokugaga with their powerful Heaven Sword, or Tenkuu-ken. As the series progresses, the Boazanians continue to come up with a variety of strategies to try to defeat the Earth's powerful new robot, always involving the production of a new Beast Knight based on a different animal. As the Voltes team trains to improve their teamwork and skill, they also learn more about the nature of the Boazanians and the Goh siblings' missing father. Professor Goh is revealed to have disappeared on a diplomatic mission to the planet Boazan itself, hoping to stop their invasion before it came to pass. Having been imprisoned by the Boazanian empire this entire time, he escapes from their control and attempts to return to earth with several allies, but is waylaid by a breakaway force and taken prisoner by Heinel's traitorous science officer, Zuhl. Much of the second half of the series revolves around the Goh siblings desperately searching for their father, while he in turn works to oppose the invaders in secret. Aside from its technological advancement, the planet Boazan is in fact very similar to Earth, and the native Boazanians are so like humanity that the two races can even healthily interbreed. The planet is wholly governed by an oligarchic monarchy with a cruel caste system: Boazanians born with horns are highly regarded and form an aristocratic elite, while the hornless are forced into slavery and worked to death on physically demanding tasks such as mining and construction. During a succession dispute between the highly-revered Chief Science Minister La Gour, son of the late emperor's brother, and Zu Zambajil, an illegitimate son of said emperor, it was discovered that despite La Gour's noble birth, he had been born hornless and had hidden the fact with prosthetics. Taking advantage of this fact to further his own quest for power, Zambajil had La Gour imprisoned and exiled his wife Rosalia, causing him great despair. After learning that Rosalia died while he was forced to work as a common slave, La Gour joined a band of hornless dissidents and subsequently led a daring insurrection against the empire, only to be easily thwarted by their vastly superior military. With no other options available to him, La Gour was forced to escape on a flying saucer and flee across the galaxy until he found himself on the faraway planet of