While on the way to visit the Princess of Tristain for her upcoming marriage to the King of Germania, war broke out. Because of the upcoming marriage, Conquista joined forces with Albion, declared war and began their invasion of Tristain. While drowning in despair over the disparity in military strength, Louise, by chance, got on board the Zero Fighter piloted by Saito. Her ability to use the legendary magic lineage "Void" awoke and she single-handedly ensured the triumph of Tristain over the army of Albion. And so we continue on from there to their next scene of battle.

(Source: MU)