Toaru Majutsu no Index Episode 21

Title: Kauntāsutoppu (正体不明(カウンターストップ)) - Unknown Entity (Counter Stop)

Date Aired: 26 February 2009

Previous Episode → 20

Next Episode → 22

Synopsis
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. Arriving at school, he learns that Komoe is doing research on AIM (An Involuntary Movement), the field of power that psychics emit. When Index arrives in class, Komoe sends her away and then introduces Aisa as the new transfer student. Instead of leaving, Index runs into another transfer student, Hyōka Kazakiri, and befriends her. When Tōma finds them later, Komoe catches Tōma skipping the opening ceremony and Hyōka mysteriously vanishes. Aisa becomes suspicious of Hyōka, recalling her as the top student at her old school but was never seen, and warns Tōma and Komoe about her. Meanwhile, Tsuchimikado meets with Aleister Crowley concerning the illegal arrival of a Necessarius mage named Sherry Cromwell in Academy City and, despite Tsuchimikado's offer to take care of Sherry discreetly to preserve the peace between Necessarius and Academy City, Crowley wants Tōma to defeat her, as his involvement will help the "key" to the Sector i - Five Elements Institution. As Tōma, Index, and Hyōka head to an underground mall for lunch, Kuroko finds Sherry and attacks her unsuccessfully when the latter summons a Golem. Though Kuroko is saved by Mikoto, Sherry escapes and casts a spell to send eyeballs throughout the city.

Adapted From
Adapted from? which chapter of manga and/or novel

Referbacks
references to previous episodes

New Characters
Hyouka Kazakiri

Sherry Cromwell

Aiho Yomikawa

New Abilities
Counter Stop

Cultural References
"easter eggs"