Touma and Index stay at the boarding house, with Touma preparing some food. Index asks Touma about how people can predict weather and wonders if it has any similarities with fortune-telling. She then questions him about how the forecaster always reminds the viewers of imminent errors in the forecast; Touma is puzzled as well, as he had ideas that the forecasting system of Academy City is flawless and accurate.
Meanwhile, outside the Earth's atmosphere, a space shuttle retrieves the remains of a certain satellite, referring to them as "Remnant".
Inside the shower rooms of Tokiwadai's dormitory complex, Misaka Mikoto complains about the school's decision to hold schoolwide P.E. lessons due to Daihasei Festival fast approaching. Kuroko tells her that it is inevitable, given their second-place standings at the said event. The Teleporter then takes the chance to ask Mikoto on a date with some hidden thoughts of showing an innocent facade that Mikoto can't resist. Kuroko then teleports on the shower stall where Mikoto is and receives a hit from her.
Mikoto eventually agrees to take Kuroko for shopping, and soon, the Level 5 Electromaster sees news about a space shuttle launched into space on one of Academy City's blimps. Kuroko leaves from her lingerie shopping and notices the news, adding that many European countries have done the same thing.
The Teleporter then persuades her to accompany her inside and after opting for dragging her inside, notices that Mikoto is interested in increasing her breast size using pads. Kuroko nervously thinks that Mikoto might be improving her figure for a man, especially the guy she collided with on the 31st of August, and notices the blush on Mikoto's face when she talked about it. Mikoto tries to keep "that guy" away from the discussion, but Kuroko is too anxious to refute her assumptions.
Soon, their conversation is interrupted when Kuroko's phone rings. It turns out that Uiharu wants Kuroko to investigate on a robbery on District 23, which is focused on aerospace technology. With that, Kuroko and Mikoto separate ways and Kuroko goes to Judgment headquarters.
Uiharu Kazari, the remaining member of Judgment present at that time, welcomes Kuroko and invites her for some tea, which Kuroko refuses, much to Kazari's disappointment. Kuroko then asks Uiharu to give her the details of the incident.
With the footage from District 23's hidden cameras, the two Judgment operatives witness two cars cornering another and taking a briefcase with the emblem of the 23rd District with them. Kuroko sees the victims as suspicious as she saw them communicating through a transceiver. Kazari also tells Kuroko that the briefcase stolen is made such that it blocks cosmic rays and is completely airtight. Kuroko thinks that the briefcase might be taken out into space, but Uiharu thinks that it is the opposite.
Kuroko decides to track down the escaping thieves, while Uiharu assists her in tracking them down. Soon, she arrives in an alley where the thieves head off to, and quickly disabled them after retrieving the suitcase.
Soon, Kuroko receives a call from Mikoto, who asks her a favor: to hide her personal stuff from a room inspection she heard from an upperclassman. Mikoto also asks the Teleporter to come home early, as it was going to rain that night up to tomorrow.
After Mikoto ends the call, Kuroko suddenly feels that the suitcase she was sitting on disappears, and a corkscrew stabs through her shoulder out of nowhere. Soon, a girl with two ponytails appear at a distance: another Teleporter. The girl introduces herself as the girl with the ability Move Point, a "superior" form of teleportation which does not require physical contact.
Kuroko confronts the other Teleporter, who effortlessly returns one of the metal pins she teleported into her side. Soon, the user of Move Point tells her that she is partially responsible for what is going on, including the news Mikoto heard of a sudden room inspection. She also discloses the fact that Tree Diagram has been destroyed, and due to this, the experiment involving Misaka Mikoto is suspended until Tree Diagram is rebuilt.
The user of Move Point reminds her of August 21, and Kuroko takes the chance to fight back at her.
Meanwhile, Accelerator and Last Order are taking a bath together. Last Order is enjoying herself making waves at the bathtub while Accelerator quietly takes his bath alone. However, is it impossible to take a bath decently with Last Order around; Accelerator receives splash after splash of water on his face as Last Order pities him for not being able to use his ability at this moment.
Yomikawa Aiho is outside, watching over the two and cursing Yoshikawa Kikyou for dragging her into Accelerator and Last Order's guardianship.
That night, in the restroom of her dormitory room, Kuroko tends to her wounds while requesting Uiharu to get more information about the Teleporter she encountered. Uiharu reports that Kuroko just fought against Musujime Awaki, Level 4 Teleporter and 2nd year student at Kirigaoka Girls' Academy. She also confirms Kuroko's observation that Awaki does not need physical contact to teleport objects. Uiharu also adds that Awaki is unable to interfere with other Teleporters, and she is noted for having a fear of teleporting herself.
She also tells Kuroko that Awaki is one of the Guides for the windowless building, much to Kuroko's shock, because she knew that the windowless building is merely an urban legend.
Uiharu soon reports that the carriers earlier were to transport the suitcase carrying a Remnant into another institution from District 23 before being intercepted by Awaki's group.
Kazari suggests to leave this issue in the hands of the Anti-Skill, but Kuroko is forced to hang up when she sees the door leading inside open. As it turns out, Mikoto has just arrived, and is checking up on her. Kuroko tries to talk Mikoto out of entering the bathroom and seeing her injuries, which worked after all, and leaves the bathroom after Mikoto heads off to personal matters.
Kuroko thinks about August 21, and what happened on that date: there has been a presence of violent winds that night, and a railyard on District 17 has been destroyed. She also remembers being requested to assist on the aftermath of the incident the day after, and her discovery of a coin which Misaka Mikoto usually uses.
Kuroko leaves the dormitory and opens a line with Uiharu; she contacts her about Musujime Awaki's involvement with an outside organization and requests a simulation of her eascape route. She has decided that she has to do something to end the nightmare that Mikoto has been hiding to her for a long time.
Soon, she hears an explosion from a distance. Kuroko sees in the middle of the wreckage her roommate and friend Misaka Mikoto fending off a group of men using her Railgun. As Kuroko closes in on the construction site where the fight is starting, Mikoto speaks to Musujime Awaki, who has the suitcase in her custody.
Awaki tells Mikoto to give up saving the ones involved in the experiment (the SISTERS) and accept the fact that they are intended to be destroyed. However, Mikoto remains adamant and admits that she has to put the responsibility to herself for what is going on.
Mikoto prepares to fire her electricity at Awaki, but the Teleporter confidently asks that she can escape her wrath unharmed. Awaki then prepares a human shield made up of civilians to make Mikoto hesitate attacking before escaping herself. Meanwhile, Kuroko realizes that it is now her turn to go into the deepest part of the battlefield.
Meanwhile, in a certain hospital room, a girl who looks exactly like Misaka Mikoto wakes up and, as her clothes fall to the ground, realizes that she is running out of time and she needs to make haste.
- Shirai Kuroko does battle with Musujime Awaki, and is left seriously injured in her hands.
- Musujime Awaki retrieves the Tree Diagram Remnant.
- Misaka Mikoto confronts Musujime Awaki and her cohorts.
By order of appearance
- Index Librorum Prohibitorum
- Kamijou Touma
- Misaka Mikoto
- Shirai Kuroko
- Musujime Awaki
- Last Order
- Yomikawa Aiho
- Yoshikawa Kikyou (mentioned-only)
- Misaka 10032
- Teleport - Shirai Kuroko, level 4
- Electromaster - Misaka Mikoto, level 5
- Railgun - Misaka Mikoto, level 5
- Move Point - Musujime Awaki, level 4
- Academy City
- Kamijou Residence
- Tokiwadai Middle School
- The hospital Heaven Canceler works in.
- Tokiwadai Dormitory
- Windowless Building (referenced-only)
- School District 17 (flashback-only)
- This episode features Mikoto wearing her floral hairpin.
- This episode marks Uiharu Kazari's official debut in the main Toaru Majutsu no Index storyline.
- Kuroko references Accelerator and Touma's battle back in episode 14.
- The Destruction of Tree Diagram that occurred in the sixth episode of the first season, is referenced during this episode.
- Kuroko references Mikoto's 'rendezvous' with Touma back in episode 18 during her shopping with Mikoto.
- Awaki references the "end of Mikoto's nightmare" which is the suspension of the Sisters Project and the Level 6 Shift.
- Index compares the weather forecast with Feng shui during this episode.
- The Mikoto and Kuroko shower scene shown in the episode, marks the third time the scene from 8th Light Novel Volume is animated. The scene was first seen the epilogue of the final episode of the first season of Toaru Majutsu no Index, and then later used in the first episode of Toaru Kagaku no Railgun anime. Though having slight differences, the scene ends with Mikoto being hurt by Kuroko after invading her shower stall.
- Which school did Tokiwadai Middle School lost to last year in the Daihasei Festival? Ans: Nagaten Jouki Academy
- Who does Awaki work for?
- How does Awaki know of the experiments?
- What was the injury Awaki had two years ago that would hinder her from teleporting herself properly? Ans: She teleported herself into a wall. Rather than teleporting herself, she pulled her leg off so the skin on her leg got peeled off.
- Why is Awaki the guide to the Windowless Building?
- Kuroko: "August 21st... An unknown storm rose that night... The railway switchyard at District 17 was obliterated. And the next day..." -Kuroko's voice-over regarding what occurred in August 21.
- Kuroko: "I'm sorry, Onee-sama. You must be harboring a deep anguish that none of us could even imagine. And you are still trying to keep me out of it. So let me take the chance to apologize. In order to stop this what Musujime calls your 'nightmare', I will have to intrude into your private matters." -Kuroko's inner monologue during her attempt to find Awaki.
- Awaki: "In the end, you're merely fighting for your own sake, no? Regret, disappointment and anger... You're just fighting those puny sentiments of yours." -said to Mikoto.
- Mikoto: "Yeah. I'm pissed off... So pissed off it feels like the veins in my head are about to burst. That idiot... Did she really think I wouldn't notice? Even through the door, her voice was... was that horrible... Yeah. I'm pissed off at my idiotic roommate and the piece of crap sitting in front of me, and most of all, at the person responsible for this mess... Myself!" -said to Awaki as a response to her statement regarding Mikoto.
- Kuroko: "It looks like it's my turn to move now. Alright... Time for me, Shirai Kuroko, to make my move... So that we can definitely return... I must go to the depths of the battlefield..."