The Three Dukes meet to discuss what to do about King Souma. In Amidonia, Gaius receives word from Georg accepting his aid, and prepares to invade Elfrieden over the objections of his finance minister. Souma delivers his ultimatum to the Three Dukes.

Gaius leads an invasion force from Amidonia into the kingdom and lays siege to the city of Altomura. Meanwhile, in Randel, the Forbidden Army constructs a fort from which they engage Georg's forces, while Red Dragon City receives its own surprise attack.

Souma and his entourage confront Vargas in his castle before hurrying off to Randel to regroup with the Forbidden Army. A stunning truth about Georg is revealed by Glaive, leading to a dramatic turn of events with Gaius and his forces at Altomura.

Under Gaius's command, the Amidonian army launches a full-scale attack to retake Van, but Souma and his forces move to stop them. In the aftermath of the war, there are serious consequences to be faced and plans for reconciliation to be put into action.