While en route to visit the Princess of Tristain ahead of her impending marriage to the King of Germania, war erupted. Capitalizing on the upcoming nuptials, Conquista allied with Albion, declared war, and launched an invasion of Tristain. Overwhelmed by despair at the vast disparity in military power, Louise happened to board the Zero Fighter piloted by Saito. Her ability to wield the legendary "Void" magic lineage awakened, and she single-handedly secured Tristain's victory over the Albion army. The story continues from there into their next battlefield.