University student Souma is suddenly summoned as a hero to the kingdom of Elfrieden, which is facing a number of crises, both foreign and domestic. Souma confers with the king and prime minister, after which the king makes a stunning announcement.

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.