Rentaro is condemned for a decision he made in battle, and is told that there is another Gastrea named Pleiades that is protecting the already supposedly immortal Aldebaran. Rentaro is forced to face the enemy alone, and is helped by someone rather unexpected: his enemy from the past.

With the addition of Kagetane and Kohina, the adjuvant is complete. They choose the Flames of Revolution, the last place humanity won their battle against the Gastrea, as the ground for the final battle against Aldebaran.