A Certain Magical Index Season 1 Episode 21

Unidentifiable (Counter Stop)

Tōma returns to school after summer break, but is followed by Index, who thinks she won't have anything to eat for lunch while he's away at school. When Index arrives in class, Komoe sends her away with money to ride a taxi home and then introduces Aisa as a new transfer student. Index ends up befriending Hyoka Kazakiri, another transfer student; Tōma later finds them trying to change into less conspicuous clothing and when Komoe catches Tōma skipping the opening ceremony, Hyoka mysteriously vanishes. Aisa becomes suspicious of Hyoka, who was a student at Aisa's old school, and warns Tōma and Komoe about her. Meanwhile, Tsuchimikado meets with Aleister Crowley concerning the arrival of Necessarius mage Sherry Cromwell in Academy City and despite Tsuchimikado's offer to take care of Sherry discreetly, Crowley wants Tōma to defeat her. Meanwhile, Kuroko finds Sherry and attacks her unsuccessfully, but is saved by Mikoto while Sherry escapes and casts a spell to send eyeballs throughout the city.