Hajime's party makes their way back to a familiar location. Deep in the Labyrinth, a new foe threatens the lives of his classmates.

Hajime completes the grueling trial at the end of the Grand Gruen Volcano labyrinth, but at that exact moment, Freid, a demon commander, launches a surprise attack. Hajime is heavily injured, and a desperate battle begins.

As Hajime's deadly duel versus Noint continues, Aiko and Tio hatch a plan to assist Hajime. The other students also notice the alarming noise and gather together to figure out what's going on.

With her trap sprung and all of the students rendered unable to fight, Eri reveals her true nature and sets the rest of her plan in motion.