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"Darkness" ( Yami?) 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 Febrie and the frog-faced doctor said Febrie is a scientifically created artificial object. The situation around Febrie only grows more suspicious.

Misaka's Sister tells Mikoto of the existence of Febrie'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 Febrie.

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 Febrie.


Mikoto is shocked to hear the truth behind Febrie's true nature, particularly the part where the "frog-faced doctor" explains how Febrie's body produces a poison that could kill her if she stops eating the lollipops she has been eating ever since. In fear of Febrie's well-being, Mikoto urges for information about where she could find the ones responsible for Febrie's creation, but the frog-faced doctor warns her that the ones linked with Febrie's existence belongs to the "dark side" of Academy City.

After talking to the frog-faced doctor, Mikoto returns to check up on Febrie and tells her friends that she can be discharged soon. Saten and Uiharu are excited to have Febrie back, but Kuroko senses that something is troubling her. Unfortunately, she loses the chance to ask her about it as Mikoto heads to her clone who is nearby.

Misaka 10032, after voicing out her insecurities over Mikoto staying up all night just to watch over Febrie's condition, eventually reveals that she found out about Febrie's "big sister" in a short conversation with her the night before. 10032 also observed some similarities in Febrie's thought patterns which she found similar to hers, which made her hypothesize that Febrie gained her knowledge through Testament as well and the one who installed them into Febrie's head was the same person who gave the Misaka Clones their memories.

Mikoto is immediately reminded of Nunotaba Shinobu, the girl who once had her hand in the Radio Noise Project, and suspects that she may have been involved in Febrie's creation as well. Misaka 10032, on the other hand, just wanted to thank Shinobu for introducing her to the taste of milk tea.

On his way back, Mikoto slowly pieces the clues she found throughout the past few days and focuses on the people who want Febrie "reclaimed". Mikoto thinks that the only way to get into the case is by asking the creators directly, so Mikoto finally decides to dive into the darkness once more.

Kongou soon calls Mikoto and asks her about Febrie. Mikoto assures her that Febrie has been discharged with a clean bill of health, and a blissful Kongou anticipates telling Kinuho and Maaya about the good news. However, this also reminds her that she owes her two friends an apology for rashly heading into Mikoto and the others and leaving them behind. Kongou's words about friends staying together amidst good and bad things alike hit hard on Mikoto, but she had little time to ponder on them as Kuroko ushers her back to the Tokiwadai Dormitory.

Mikoto decides to prepare for a solitary mission for Febrie's sake, but Kongou's words continue to haunt her. However, she decides to push on, even saying the usual alibi to Kuroko. But unexpectedly, Kuroko seems fine with her leaving for the rest of the day. Mikoto then remembers about her short conversation with Kuroko during the time when she is still fighting against those responsible for killing her clones.

At that moment, Mikoto decides to tell the truth to Kuroko, Uiharu and Saten in the latter's house.

The four girls are shocked to realize Febrie's true nature and Saten is clearly concerned about the little girl's well-being. However, Mikoto warns her friends that trying to save Febrie would mean facing a threat beyond the reach of the authorities and she is unsure that she will be able to protect them all. To Mikoto's surprise, the three has shown their determination in helping her out.

Soon enough, in the Judgment headquarters, Uiharu has started looking for any traces of activity related to Febrie and the Powered Suits similar to the one that attacked Mikoto and the others the day before while Mii goes to babysit Febrie for the meantime. Saten tries to contribute as well by trying to look for ways to reproduce the lollipops that Febrie constantly eats, but even the frog-faced doctor was unable to give her any answers.

Meanwhile, Kuroko and Mikoto personally ask Yomikawa Aiho about the Powered Suit and security robots taken by the Anti-Skill as evidence. Unfortunately, Aiho tells them that the main headquarters of Anti-Skill had taken over the case so the evidence has been taken there as well. Mikoto and Kuroko left a bit disappointed by this dead end, but Aiho decides to catch up to them and gives a transparent case with a strand of hair inside, found inside the Powered Suit taken the day before. Aiho explains that she decides to give it to them instead of leaving it be confiscated by the main headquarters, and soon warns them not to try meddling too deep into the case.

Mikoto and Kuroko soon return to Branch 177 of Judgment with the news, and the others quickly deduce that the "underground organizations" Mikoto had warned them about may have been the ones responsible for taking away the evidence. Uiharu also found nothing except a camera blackout that happened during the Powered Suit incident. Saten then remembered that their phones did not work during that time as well, and Kuroko mentions an incident of malfunctioning traffic lights at the same time period. Kongou also comes out with nothing about the suspicious man they saw the day before, although she agreed to help with the Powered Suit case as her father's corporation handles a research facility that specializes in Powered Suits.

Kuroko goes competitive against Kongou and decides to go out to search for more clues, and Saten and Uiharu follow suit. Meanwhile, Mikoto suddenly has an epiphany.

After remembering Misaka 10032's observations and the mystery behind Febrie knowing Mikoto's name, Mikoto feels that Shinobu's involvement is becoming clearer to her. That leaves her motives yet to be determined.

Meanwhile, in the headquarters of STUDY, the group discuss their actions against Anti-Skill prying into their plans and is trying to double-check the smooth progress of their plans for the upcoming Academy Exhibit.

The girl, known to many as Nunotaba Shinobu, assures them that she will do her best for their presentation.

Elsewhere, in the middle of her investigation, Mikoto finds out that Shinobu was expelled from Nagatenjouki Academy. That leaves her with one lead: the mysterious case containing a filament-like substance inside. She visit the frog-faced doctor for his opinion on what it is, and he reveals that it is a strand of hair taken from someone similar to Febrie... a "sister", as Mikoto speculates.

Then, the frog-faced doctor decides to tell her some related news about Febrie. After his analysis of the candy Saten brought to him previously, the frog-faced doctor estimates that the lollipops in Febrie's possession would only last for 72 hours, pressuring Mikoto to pursue Febrie's creators even more.

Just like last time, the frog-faced doctor asks Mikoto if she is brave enough to face the "darkness" of Academy City. Upon hearing Mikoto's affirmative response, the frog-faced doctor decides to help out by setting up an appointment with someone from the "darkness" itself.

Someone very familiar to her. The woman named Therestina Kihara Lifeline.

Major Events

  • Febrie 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 Febrie.
  • 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.


New Characters

No new characters were introduced in this episode.


New Locations

No notable locations were introduced this episode.


  • 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.


  • 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.


  • Mikoto references her fight with ITEM though does not name them nor speak out on why she fought them.
  • Uiharu references the traffic jam back in episode 18.

Cultural References

No notable references to culture were introduced this episode.

Differences in Adaptation

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 Febrie's bag and clothes on a table is reused later in the episode when Heaven Canceller talks about Febrie having only 72 hours before her lollipops run out.


# Title Time Scene & Notes
Unverified Track Opening
Unverified Track
Unverified Track Eyecatch
Unverified Track
Unverified Track Ending
Unverified Track Preview

Unanswered Questions

  • What was the experiments that made artificial humans called?
  • Febrie is a spare of what or who?


  • Heaven Canceller: "I suppose that's the normal reaction. Common sense would dictate that it's impossible, but every so often, people try to surpass common sense. Surely, by now, you know that."—said to Mikoto after she doubts Heaven Canceller's words.
  • Misaka 10032: ""I saw that you waited through the night for her treatment to finish. You haven't even visited your little sister in a while,... so I figured that she must be very important to you," says MISAKA as she puts on a hurt expression, creating a gloomy atmosphere."—said to Mikoto regarding Febrie.
  • Misaka 10032: ""She taught me the taste of milk tea. If possible, I'd like to see her again, and thank her," says MISAKA as she voices a small wish."—said to Mikoto regarding Shinobu.
  • Kongou: "When I told them about what happened yesterday, they were upset that I'd gone alone. They told me, "True friends share both joys and dangers alike." If I were in their shoes, I'm sure I'd also blame myself for not being there to help. I didn't take their feelings into account. It looks like I've still got a ways to go on the path of friendship!"—fateful words said to Mikoto.
  • Shinobu: "My utmost. I'll do what I can."—to STUDY member.
  • Heaven Canceller: "I'll ask you once more. Do you have the courage to face the darkness in this city? Even if you yourself will bear the pain?—to Mikoto.
  • Therestina: "Oh? Long time no see, little guinea pig."—to Mikoto.


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