An Impossible Choice...As the Electoral War rages and the Primogenitors vie for dominance, Itogami Island plunges into disarray. Shio and Yuiri escort Avrora to the island in a bid to bring the conflict under control, only to come face-to-face with the Second Primogenitor, Fallgazer. While Yukina heads off alone to rescue her allies from Fallgazer's clutches, Kojou's powers run wild, afflicting him with unbearable hunger and thirst. And in the lead-up to the final showdown with the Order of the End, the World's Mightiest Vampire learns he must pay a terrible price to prevent his abilities from wiping out everyone dear to him...