Toaru Kagaku no Railgun S Episode 21

Darkness (闇) is the twenty-first episode for the second season for the Toaru Kagaku no Railgun anime adaption, and the forty-fifth episode overall. It was first broadcasted on September 6, 2013. The script was written Tsuchiya Michihiro, directed by Sakurabi Katsushi, and storyboarded by Nihei Yuuchi. The animation was co-directed by Fujibe Ikuma, Kumagai Katsuhiro, Naoya Takashi, and Ishii Tetsuya.

Someone is trying to retrieve Febri and the frog-faced doctor said Febli is a scientifically created artificial object. The situation around Febri only grows more suspicious.

Misaka's Sister tells Mikoto of the existence of Febri's "older sister" and the traces of the "Testament". With hints the dark side is possibly involved, Mikoto decides she cannot tell Saten and the others, but an offhand comment from Kongou leads them all to decide to save Febri.

Not even Anti-Skill can touch the deep darkness of Academy City. Now that they know it exists, Saten and the others immediately beginning thinking up a plan to save Febri.

Major events

 * Febri is discovered to be an artificial human that had knowledge inputted into her through Testament, and that her body produces toxins that could kill her. She later has 72 hours before her entire stock of lollipops that stay those toxins is depleted. Moreover, the hair that's inside a capsule is discovered to be from a being that is similar to that of Febri.
 * Mikoto deliberately involves her friends in the dark side of Academy City.
 * Mikoto discovers that Shinobu has been expelled from Nagatenjouki Academy.
 * Mikoto meets Therestina Kihara Lifeline in a desperate attempt to find a lead.

Adapted from
This episode features original content, as such it is not adapted from any previous material.

Characters

 * Febri
 * Misaka Mikoto
 * Heaven Canceller
 * Frenda Seivelun (flashback-only)
 * Mugino Shizuri (flashback-only)
 * Shirai Kuroko
 * Uiharu Kazari
 * Saten Ruiko
 * Misaka 10032's cat
 * Misaka 10032
 * Kongou Mitsuko
 * Ekaterina
 * Konori Mii
 * Yomikawa Aiho
 * Aritomi Haruki
 * Kosako Shunichi
 * Sekimura Hirotada
 * Sakurai Jun
 * Madarame Kenji
 * Nunotaba Shinobu
 * Therestina Kihara Lifeline

New Characters
No new characters were introduced in this episode.

Locations

 * Academy City
 * School District 7
 * Heaven Canceller's Hospital
 * Tokiwadai Dormitory
 * Saten Residence
 * Judgment 177 Branch Office
 * Anti-Skill District 7 Main Office

New Locations
No notable locations were introduced this episode.

Abilities

 * Electromaster (Railgun-variant) - Misaka Mikoto, Level 5 (flashback only)
 * Meltdowner - Mugino Shizuri, Level 5 (flashback only)

New Abilities
No new abilities were introduced during this episode.

Trivia

 * Shinobu speaks for the first time since being reintroduced.
 * The ending theme is removed to extend the content of the episode, though the track Tachi Tomare nai Riyuu from the second Toaru Kagaku no Railgun soundtrack is played over the credits.

Referbacks

 * Mikoto references her fight with ITEM though does not name them nor speak out on why she fought them.

Cultural References
No notable references to culture were introduced this episode.

Animation Trivia

 * Scenes from 2, 5, and 6, are reused for flashbacks regarding the Sisters, moreover, of that Nunotaba Shinobu.
 * Kuroko's face that was shown at the end of episode 7 is reused as a flashback just before Mikoto tries to involve her and the others against the dark side of Academy City.
 * Scenes from episode 8, 9, and 10 are reused for Mikoto's flashbacks regarding the "dark side organization" she fought.
 * The still of Febri's bag and clothes on a table is reused later in the episode when Heaven Canceller talks about Febri having only 72 hours before her lollipops run out.

Unanswered Questions

 * What was the experiments that made artificial humans called?