Toaru Kagaku no Railgun T Episode 24

Diffusion (拡散) is the 24th episode of Toaru Kagaku no Railgun T. It was broadcast on September 18th 2020. The episode was directed by Tanaka Tetsuro, Ranzaki Akari and Mori Yoshihiro, the screenplay written by Yasukawa Shogo, and storyboarded by Iida Takashi and Nagai Tatsuyuki.

The Doppelganger transforms into a massive form after gathering debris through "soul possession". With the massive beast and its overwhelming mass standing in her way, Mikoto creates an iron sand colossus against it. By taking advantage of the properties of iron sand, Mikoto slowly breaks down the Doppelganger's creation, while the Doppelganger fights back by trying to send fuel tanks crashing onto the nearby urban area.

Mikoto was barely able to defend herself against the fuel tanks exploding in mid-air, but the Doppelganger's actions not only enable her to turn Mikoto's attacks against herself; it also exposes the location of the stealth airship that stores the backup data of the research facility. Meanwhile, Kuriba heads towards the origins of the Doppelganger to settle things once and for all.

Characters
By order of appearance:
 * Misaka Mikoto
 * Doppelganger
 * Saten Ruiko
 * Uiharu Kazari
 * Shirai Kuroko
 * Kuriba Ryouko
 * Leader
 * Seike
 * Naru
 * Yakumaru
 * Shokuhou Misaki
 * Chief
 * Keitz Nokleben

Abilities

 * Artificial muscle/mold mix manipulation - Doppelganger (previously believed to be 'Soul Possession')
 * Electromaster (Railgun-variant) - Misaka Mikoto, Level 5
 * Predator - Leader, Level 3
 * Perfect Paper - Naru, Level 3
 * Mix Master - Yakumaru, Level Unknown
 * Stick Slip - Seike, Level Unknown

Locations

 * Academy City
 * School District 7
 * A Certain Iron Railway Bridge
 * Saten Residence
 * Tokiwadai Dormitory
 * School District 20
 * Shinasame University DNA Map Analysis Laboratory (flahsback)

Trivia

 * The iron bridge seen in previous Toaru seasons (prominently in the Sisters Arc) is briefly seen in this episode, when Mikoto blast the first gas tank raised by the Doppelganger.

Referbacks

 * Kuroko remembers Mikoto's promise that she will call her if anything comes up back in .
 * Scenes from the three previous episodes are used as flashbacks, when Leader explains to Mikoto and Misaki on how the abilities of the Doppelganger work.

Cultural References

 * The Doppelganger tricked Mikoto on using iron sand bullets onto the tanks. This caused the iron sand in the atmosphere to generate a magnetic field and stick onto the airship, with charged particles from affecting it. This explains why the Doppelganger be able to detect the otherwise invisible airship with her eyes that detects magnetic fields.
 * The Doppelganger references, a story of a simple girl who becomes a princess by magic, where it only lasts till midnight. Here in this episode, the Doppelganger compares the airship to the aforementioned princess, and the iron sand to the expired magic that reveals its true form.
 * is an informal name given to several kinds of unrelated eukaryotic organisms that can live freely as single cells, but can aggregate together to form multicellular reproductive structures.
 * According to Railgun manga editor Ogino Kentarou, the two things that the Doppelganger based her artificial muscles on are  and muscles of a gorilla.
 * Ophiocordyceps unilateralis is a fungus which infects ants, becoming a parasite that eventually grows enough to burst out of the ant's carapace and take over its brain, controlling the ant like a zombie until it dies, after which the fungus uses the corpse as nutrition to spread its spores.
 * A gorilla has gut bacteria that allows it to digest cellulose, a compound extremely common in plants, which provides its muscles with enough energy to maintain its strength even without heavier foods, the reason why the muscles of a gorilla are super strong.

Differences in Adaptation

 * Due to censorship reasons, the Doppelganger already had white-threaded clothes when she appeared out of the 'giant puppet' in this episode. In the manga, she was still naked at that time until she gained these clothes at the airship.
 * The adaptation cut a scene of Ryouko from the manga where she sent a basic design of the cyborg to the chief to save her mother.
 * Scenes of Saten and Uiharu mistaking a tank blown by Mikoto as fireworks, as well as Kuroko humping on Kill Bear are anime-original.
 * In this episode, Ryouko used a motorcycle to chase down the Doppelganger. Originally, she used a scooter.
 * Naru's paper jet used a ramp to launch itself into the sky, unlike in the manga where they flew away immediately without a ramp.
 * Mikoto did not fall off the airship in the manga.

Animation Trivia

 * At least 25 seconds of footage from the is reused in the beginning of the episode before actual original scenes for the episode are seen.
 * Both the giant puppet created by the Doppelganger and the iron sand puppet created by Mikoto are rendered in CGI.
 * The pose of the iron sand puppet where it fired an iron sand bullet, in one of the shots, resembles the pose that Misaka Mikoto does when she fired her Railgun back in .

Unanswered Questions

 * Who is the person that the chief talked with?
 * Did Mikoto finally defeat the Doppelganger?