In Shahal City on the planet Al Shahal, Hayate Immelman discovers a stowaway named Freyja Wion in the shipping docks. Freyja stowed away to run away from an arranged marriage and to audition for the idol group Walküre on the planet Ragna, but Hayate informs her that she is on the wrong planet. When a Vár outbreak suddenly causes Zentradi soldiers to go rogue and attack the city, Walküre and Delta Flight scramble to contain the threat, but are later on met by the Aerial Knights in a fierce dogfight. During the battle, Freyja sings along with Walküre and assists with suppressing the Vár while Hayate commandeers an abandoned Valkyrie and uses it to protect Freyja.

With the N.U.N.S. fleet wiped out by their own weapons, the final battle on Ragna is now just between Chaos and the Windermereans. Seeing the burden of shouldering the deaths of countless lives, Heinz ponders on negotiating peace talks with the N.U.N.S. while Roid prepares Mikumo on the Star Temple. Heinz orders Mikumo to sing the Song of the Stars, sending delta waves throughout the Brísingr Cluster, only to realize that Roid's objective is to bring the entire galaxy under his sole control in a Vajra-style hive mind. As both factions are mentally trapped by Mikumo's song, Heinz urges the Aerial Knights to take down Roid while Freyja tries to free her comrades from the spell. Hayate, Freyja, and Mirage's feelings for each other enable Chaos and the Aerial Knights to break free, and the combined might of Walküre releases Mikumo from Roid's control before both factions break through the Star Stage. As Hayate, Mirage, and Freyja rescue Mikumo, Keith ends the conflict by killing Roid before he himself is consumed by the destruction of the Star Stage. In the aftermath of the battle, Heinz orders the remaining Windermerean forces to retreat as the Brísingr Cluster is freed from Windermerean control.