Stiyl explains the dead knight was from the 13 Knights of the Roman Catholic Church and that a magical barrier is concealing all magical occurrences inside the school from the public. Toma and Stiyl are forced to separate when the students, under the control of a spell, cast an imitation of Gregorio's Choir to attack. When Stiyl destroys the spell's source, he finds Aureolus Izzard while Toma runs into Aisa Himegami. Aisa reveals that she came to Aureolus willingly because the Misawa Cram School is able to repel vampires; her blood attracts and kills vampires, who- save their need to drink blood- are otherwise ordinary people. Tired of the implications of her powers, she came to Academy City and met Aureolus, who agreed to help her with her powers if she used them to lure vampires to Misawa in order to save someone important to him. When Aureolus finds them, Aisa confronts him about his objectives and threatens to leave if he continues to kill people. He agrees to stop but seals Toma and Stiyl's memories, and they awaken outside the school without any recollection of their mission until Toma uses his Imagine Breaker to nullify the spell. Meanwhile, Index has followed Stiyl's mana trail to the school and is put to sleep and captured by Aureolus. The remaining 13 Knights attack the school with a true version of Gregorio's Choir, but it is restored by Aureolus's true power: Ars Magna. Toma finds Sphinx outside with Index's habit and realizes that Index is now inside the school.