What Is a Traitor?.The Kaiju Eugenicists reveal that they and Gauma used to be comrades, and ask him to rejoin their ranks, to which he refuses. Realizing they are at a disadvantage without a kaiju, the Kaiju Eugenicists retreat. The next day, Yomogi meets Yume at school, where she tells him how she and her older sister, Kano, were never particularly close, but Kano went out of her way to invite Yume to her music recital shortly before she died. Yume had been left wondering why Kano reached out to her then, and gets the contact information for one of Kano's classmates, Kanae. Meanwhile, Koyomi runs into Yomogi's part-time boss, Inamoto, who happens to be an old classmate of his, and Chise begins to feel jealous...