Imaginary Number School District - Five-Element Agency.Tōma pursues Hyōka but encounters Sherry instead and is forced to fight her. He learns Sherry once had a friend named Ellis who was an esper involved in an experiment between Necessarius and Academy City twenty years ago to create the first esper-magician hybrid but suffered from the experiment and was killed by the Knights as the experiment was a violation of the truce between science and magic. To prevent this tragedy from occurring again, Sherry intends to divide both sides forever through conflict. Outraged that Sherry does not believe that people who are different like Index and Hyōka could be friends, Tōma successfully defeats Sherry. However, doing so results in Golem Ellis above ground losing control, and Index is cornered until Hyōka suddenly appears and destroys the golem each time it reforms. After Tōma arrives to deliver the finishing blow, Index and Hyōka reconcile, and Hyōka later fades away to the Imaginary Number School District. Meanwhile, Tsuchimikado confronts Aleister upon realizing the latter was behind the whole incident all this time to test the Imaginary Number School District and warns him that Tōma will be his enemy if he keeps using him. As each of the characters settle back into their daily lives, Stiyl meets with the Archbishop of Necessarius, Laura Stuart, who decides that Necessarius will need Index and Tōma's help for an upcoming problem as Kaori is missing in Japan after the events of Angel Fall.