In the 26th century, Earth is united under the banner of the UEC, the United Earth Coalition. 100 years ago, it had seemed like Earth would have been conquered by the alien power known as the Vidivician Empire. But after that threat had passed, the UEC was free to expand their dominion. Spearheading the defense of Earth Space are the Independent Military Groups, also known as the Legions. Follow the Cisalpine Legion, the 13th, as they face off various threats to Earth Space.