Toaru Kagaku no Railgun T Episode 21

Doppelganger (ドッペルゲンガー) is the 21st episode of Toaru Kagaku no Railgun T. It was broadcast on August 28th 2020.

Characters
By order of appearance:
 * Misaka Mikoto
 * Shokuhou Misaki
 * Hazamaya Kana
 * Indian Poker Trader (flashback)
 * Kinuhata Saiai (flashback)
 * Shirai Kuroko
 * Uiharu Kazari
 * Konori Mii
 * Yanagisako Aomi
 * Tessou Tsuzuri (cameo)
 * Yomikawa Aiho (cameo)
 * Keitz Nokleben
 * Kuriba Ryouko
 * Kouzaku Mitori
 * Dolly
 * Tokiwadai Dorm Supervisor (mentioned)
 * Accelerator (fantasy)

New Characters

 * Doppelganger
 * Chief
 * Female Researcher
 * Leader
 * Yakumaru
 * Naru
 * Scavenger Liaison (voice only)
 * Seike

Abilities

 * Mental Out - Shokuhou Misaki, Level 5
 * Electromaster (Railgun-variant) - Misaka Mikoto, Level 5
 * Liquid Shadow - Kouzaku Mitori, Level 4

New Abilities

 * Predator - Leader, Level 3

Locations

 * Academy City
 * School District 7
 * Judgment 177 Branch Office
 * School Garden (flashback)
 * Tokiwadai Dormitory
 * School District 20
 * Shinasame University DNA Map Analysis Laboratory

New Locations

 * Learning Core (mentioned)
 * Shinshikimi Middle School (mentioned)

Trivia

 * The unnamed controlled girl and woman are voiced by Sasaki Hitomi and Komatsu Naoko respectively.
 * The unnamed ramen restaurant chef is voiced by Yamane Masashi.
 * The unnamed female researcher in Total Human Cyborg Replacement Project is voiced by Kousaka Saki.
 * The unnamed delinquents are voiced by Iwanaka Mutsuki, Kimura Hayato, and Mizukoshi Ken.
 * The whiteboard during Uiharu and Kuroko's presentation shows that the date in-universe that day was October 11.

Referbacks

 * Mikoto once again remembers her with Misaki at the beginning of the episode.
 * Kana references Mikoto's participation in the Daihaseisai, specifically the and.
 * A scene from  is used as a flashback when Mikoto notices that the trader had disappeared from his usual place.
 * The information leaking from the School Garden that Uiharu reports was previously mentioned in Toaru Majutsu no Index Light Novel Volume SS.
 * The Shinasame University DNA Map Analysis Laboratory is one of the facilites of the Level 6 Shift Project that Mikoto destroyed via cyber hacking back in .
 * The Scavenger Liaison refers to Scavenger's  to eliminate DA, which they  due to Accelerator's intervention.

Cultural References

 * Mikoto references the by Dr. Duncan MacDougall. MacDougall hypothesized that souls have physical weight, and attempted to measure the mass lost by a human when the soul departed the body. During the experiment, one of his six subjects lost three-fourths of an ounce (21.3 grams).
 * Misaki's explanation of Kuriba Ryouko if they are the same when separated as cyborgs might be a nod to the, a thought experiment that raises the question of whether an object that has had all of its components replaced remains fundamentally the same object.
 * is a German word which literally means double walker. In fiction and mythology, a doppelgänger is often portrayed as a ghostly or paranormal phenomenon and usually seen as a harbinger of bad luck or doom. Other traditions and stories equate a doppelgänger with an evil twin, as shown in this episode.

Differences in Adaptation

 * Given the state of Uiharu's arm in this episode, the meeting in Judgment 177 Branch Office takes place after the events of October 9th (specifically October 12th, as shown on the airship screen and cafe board), unlike in the manga where Uiharu's arm seems normal, thus taking place before October 9th.
 * In relation to the statement above, the meeting in the manga is much longer than the adapted episode, especially where they explained further the machines that creates Indian Poker cards. Additionally, many of Uiharu's lines are spoken by Kuroko in the anime.
 * Both Kouzaku Mitori and Dolly appeared in person in this episode, donning their attires for their appearance in the Jailbreaker Arc, unlike the manga where Mitori's mini Shadow Puppet only appeared alongside her voice.
 * The scene of Mikoto and Kuroko inside the dorm before the former infiltrates the cyborg facility is anime-original.
 * The scene where Mikoto remembers the news of her infiltrating facilities for the Level 6 Shift Project and being referred to as a boy is done while she is on her way to the facility, unlike in the manga where she recalls it at the facility itself.
 * The scene where Skill-Out delinquents mentioned selling fake Indian Poker cards before the Doppelganger goes inside the facility is cut.
 * The scene with Scavenger is slightly altered in the adaptation. Here, the discussion happened in their base, with the Scavenger Liaison reminding them of their previous failure and how they must not fail again. In the manga, this happened inside a certain mall near the restrooms, but without the appearance of the Scaveneger Liaison.

Animation Trivia

 * During Scavenger's appearance at the end of this episode, the ending theme plays over it, which results in the ending animation being almost completely replaced, except for the end.

Unanswered Questions

 * What are the fates of the Skill-Out gangs inside the facility after they encounter the Doppelganger?
 * In what manner will Scavenger deal with the Doppelganger?