Highest Seat Does Not Hold Two

After thousands of years of conflict, the human race had finally learned to live in harmony. Then aliens came. Though conquered by an intergalactic federation, in face of the adversity, the human race chose not to return to their prejudices; instead, they biased against nonhumans. Fate cast the 'race far from their planet. Fortune, however, made the army of the federation so bureaucratic that it was compelled to document the location of Earth. But as luck would have it, the one person capable of finding the planet despises the rest of his kind for reasons no one knows. A marine sniper, who hates killing, and a gentleman of a terrorist must convince the man to join them and strike into the heart of the dastardly federation to recover their lost homeland.