After having been victorious in the battle for the Free City, Luna and her allies begin taking important bases of the Empire.
However, while getting very close to the Imperial Capital, Luna is confronted by an opponent who is totally out of her league…
Now Luna must escape captivity again. Will she be able to make her escape and finally take down the Empire!?
Slave's Sword is the story of Luna, a former aristocratic knight of the Empire. Now living peacefully as a mercenary, she quickly becomes involved in a scandal that results in her enslavement. Can Luna recapture her freedom and escape from her predicament?