Within the span of a single day, three noteworthy events occur.The first two stories involve Touma. One of which involves him protecting Misaka from a mysterious stalker, Unabara Mitsuki, while the other story has Touma going after Yamisaka Ouma, a magician who is after one of the grimoires inside Index.The third story centers around Accelerator who, for the first time in the protagonist role, deals with the remnants of the Level 6 Shift project. Seeking redemption for his role in the Level 6 project, Accelerator decides to become the protector of Last Order, the final Misaka clone that is the command center for the entire Misaka clone network. As a result, Accelerator is left to deal with Amai Ao, a Level 6 project researcher who implanted a virus within Last Order in an attempt to infect said network. Accelerator ends up suffering permanent brain damage during the event.
A month before the events of the arc, Etzali was tasked to infiltrate the Kamijou Faction, after being deemed by his magic cabal, the Return of the Winged One, as a threat to the balance of the magic and science side. As such, he enters Academy City and later abducts Unabara Mitsuki, the grandson of the Director of Tokiwadai Middle School, in order for him to steal his image and form and to get closer to Misaka Mikoto, and eventually take her form and then later take down Kamijou Touma, however, he unexpectedly falls in love with her.At an undetermined time prior to the beginning of the arc, Yamisaka Ouma had met a girl in the hospital whom had cursed markings over her body. Mistaking him for a funeral worker, the girl had several conversations with Ouma who had begun to realize that this girl was cursed to die and that she had accepted her inevitable fate. Over a period of time, Ouma began to fall in love with the cursed girl and seeked to save her life through magical means. On August 31st, he enters Academy City in hopes of extracting a grimoire from Index that will presumably save the life of the woman he loves. This action, as well as the fact that he has fought them just to get in, would later alert the movements of Anti-Skill, putting them on high alert.After the defeat of Accelerator at the hands of Touma, the Level 6 Shift experiments involving the 20,000 sisters had finally ended. As a result, Amai Ao—investor and director of the experiment—is heavily indebted after the failure of the project and installs a virus into the 20001st sister Last Order, a week before August 31. As part of a self-defense program, Last Order breaks out of her incubation chamber, and later seek the help of Accelerator to return her to the researchers to complete her development. However, this self-defense program was an unexpected for Ao, and as a result, he is forced to search for Last Order who has become a street urchin, somehow getting by, and leaving no traces in Academy City, though since she isn't completely adjusted yet, her body is slowly deteriorating.In the meanwhile, a great restlessnesss has come upon Accelerator, sensing that he has somehow changed after being defeated by Touma, which is apparent in his actions, no longer getting aggressive at the people who continually try to challenge or test his powers—which has increased now that word has gotten to them that he has been defeated by a Level 0.
First Story: Etzali's InfiltrationAugust 31, 12:00 midnight. Touma discovers in the middle of the night that due to his excursion during the summer with the magic and science sides, he has yet to do any of his summer homework, with roughly 24 hours left for him to do it all.Meanwhile, at the same as this, Accelerator passes by the Kamijou Residence after defeating a dew of delinquents trying to attack after rumors floated about that he was defeated by a Level 0. Accelerator notes that there is something different about him after being defeated by Touma. He later discovers one of the Misaka clones following him, Misaka 20001, also known as Last Order. She tells Accelerator that since he has connections with the researchers, he might be able to contact them to help her get to an incubator since her body is still incomplete, though Accelerator is apathetic about this, Last Order continues to follow him, eventually arriving at his apartment, where both she and Accelerator discover that it has been ruined by persons unknown. Regardless of this, Accelerator allows Last Order to stay in his apartment overnight; Accelerator later sleeps afterwards.August 31, 8:00 AM. Misaka Mikoto makes an attempt to enjoy her final day of summer vacation by (somewhat involuntarily) going out to buy a manga for Tsuchimikado Maika. As she heads out, the grandson of the director of Tokiwadai Middle School - Unabara Mitsuki follows her; she notes that he has been trying to follow her everywhere all week, and her attempts to discourage him has been a failure (since she cannot handle him the same way she does with any regular male who accosts her), and he is determined to accompany her wherever she plans on going, much to her frustration. Meanwhile, Touma walks by near Tokiwadai Dormitory, where he is with Tsuchimikado Motoharu and Aogami Pierce. Here, Touma tries to convince them to help him out with his unfinished homework, however, they are obviously unconcerned about it, and their conversation devolves into their preferred female character archtypes. Conveniently, Touma, Motoharu and Pierce happen to walk by Mikoto, and as a last ditch effort to rid herself of Mitsuki's company, Mikoto claims that she was waiting for Touma for a date. Which fairly surprises both Motoharu and Aogami, and putting Mitsuki in a state of dejection. However, several students in the Tokiwadai Dormitory, have also seen the event unfolding with Mikoto and Touma; most notably Shirai Kuroko who is shocked to see Mikoto with Touma, as well as the Tokiwadai Dorm Supervisor impressed at Mikoto's brazen choice of meeting with a boy in front of the dormitory. With this, Mikoto is forced to run away with Touma in her grasps.
After getting Touma to agree with her plan, Mikoto explains how she’s been continuously stalked by Mitsuki and decides to take the opportunity to convince him that she’s going out with Touma in order to get him to lose interest. Touma however, is unenthustiastic about it as he has yet to do his summer homework. After an embarassing situation with Mikoto involving hotdogs that she bought for the two of them, Touma asks what they could do look like a real couple. In an effort to look more like a couple, Touma and Mikoto decide to have idle talk which eventually leads to Mikoto informing Touma that less than 10 Sisters remain in Academy City after the events of the Sisters Arc while the rest are out getting bodily repairs outside of the city. After easily helping Touma with his homework, Mikoto leaves Touma to go get drinks; while waiting for Mikoto, Touma spots Mitsuki and engages in conversation (while having him help with his homework), quickly learning that he genuinely likes Mikoto.Upset with the current situation, Mikoto scolds Touma for befriending Mitsuki; however Touma is able to convince her that Mitsuki has no ill intentions and suggest that they call off her their fake date. Mikoto becomes guilty and hurt because of this, though she reluctantly agrees but decides to treat Touma to lunch before they part ways, as a way to repay for all he has done for her today, assuring to Touma that she will handle Mitsuki herself from now on. While Mikoto makes her way through the crowd of the fast food restaurant, Touma and Mistuki once again meet eachother; though while the two chat, Touma spots a man that looks exactly like Mitsuki running into the fast food restaurant. Touma suspects that Mitsuki has a twin brother but Mitsuki assures him that he is an only child. Meanwhile as Mikoto makes her way out of the restaurant, the Mitsuki lookalike frantically warns her to run, much to Mikoto’s confusion.Outside the restaurant, Mitsuki suspects that the lookalike that Touma saw is the work of an esper with the ability to change appearance and kindly ask that Touma goes to check the situation. Touma agrees to go but as he runs off he is punched in the back by Mitsuki, now carrying an obsidian dagger, and attacks with it. Though confused with the situation, Touma deduces that the man he has been talking to is not Unabara Mitsuki but before he can make any sense of what’s going on magical attack produced by a black dagger wielded by Mitsuki. After seeing the scale of what the attack could do and as to not involve minimize innocent bystanders, Touma begins to run for his life hoping to lead him to a secluded location, while Mitsuki gives chase.While being chased by the impostor, Touma calls Index to see if she is fine as well as ask her on how to defeat the magician. Index says that the magician is using a replica of the Spear of Tlahuizcalpantecuhtli (an Aztec deity), which uses the light from the reflection of Venus to destroy things; Index states that Touma can use his right hand to block the attack. Touma also asks about how the impostor turned himself to Unabara Mitsuki, to which Index states that the Aztec practice the skinning of sacrifices so that they could wear them, however, Index states that if its only for a disguise the impostor only needs a small portion of it. After hearing this, Touma cuts-off Index after stating his disgust for magicians which Index found insulting.
With nowhere to go, Touma runs into an empty construction site with the impostor right behind him. To keep the impostor from using the obsidian spearhead, Touma quickly uses a shovel full of cement dust to cover the impostor. Now with his weapon reduced to an ordinary dagger, the impostor is forced to fight Touma on his terms, though with the dagger he still has an advantage. Even the with his confusion, Touma is able to punch the impostor in the face, breaking his mask and revealing his face Touma. With the impostor down, Touma demands answers from him. The impostor tells Touma that he was sent to Academy City because his organization believes that a growing faction composed of the Index Librorum Prohibitorum, power magicians, as well as a level 5, is threatening the balance the world; that is the Kamijou Faction, an unstable but influential group that can destroy the balance of the world. The impostor continues by saying that his true target isn't simply Touma but the entire members of the faction, and his method was to destroy the faction from within by dissolving the relationships between the members. Suddenly, the impostor grabs hold of his obsidian spearhead and wipes the cement dust off, and then prepares for another attack on Touma; he fumbles his attack however, hitting the steel girders above instead, and giving Touma an opening to punch his obsidian spearhead, destroying it in the process. While the building slowly collapses, Touma tells the impostor that he thought that he could be friends with him, though the impostor simply ridicule him for this; Touma asks the impostor if his feelings for Mikoto were false as well, to which the impostor responds by saying what is wrong for an impostor having feelings, and continues by saying that there is nothing wrong with an impostor like him for having feelings for Mikoto. The impostor states that he didn't want to do this, and it is all Touma's fault that he has to lie to Mikoto. At this point Touma realizes that the impostor actually likes Mikoto.
With the impostor being resolute at being Touma's enemy, Touma declares that he will destroy his illusions. With that, both Touma and the impostor go head-to-head inside the empty construction site. However, while they fighting the entire structure of the building collapses, and steel girders hits the impostor even though Touma tried to save him. When the smoke clears, Touma finds himself unharmed between steel girders being magnetically balanced as to not crush him, to which Touma immediately thought it was Mikoto's doing. Touma then sees that the impostor is pinned down by the steel girders; with the magician defeated, the impostor warns Touma that attacks will continue and asks to protect Mikoto, to be whenever and wherever she needs Touma, which he obliges. Meanwhile, Mikoto overhears their conversation and blushes to Touma's reply.August 31, 1:04 PM. marks the end of the Etzali event.
Second Story: Yamisaka Ouma
August 31, 3:15 PM. After his fight with Etzali, Touma continues to try and do his homework back at his apartment, and is later forced by Index to go out for dinner.Later, after both Touma and Index left the building, Ouma, a magician wearing an Azusayumi gauntlet on his right hand, successfully enters Academy City, after defeating the Anti-Skills, and arrives at the apartment building looking for Index. He uses his magic to jump several stories and attack Touma's dormitory, ruining it. However, he discovers that no one is home and later uses another magic spell to search for her.August 31, 6:00 PM. Meanwhile, Touma and Index are in a certain restaurant, where Touma still struggles to finish his summer homework.
However, Ouma discovers them and attacks Touma, destroying a part of the restaurant. Touma survives the attack by blocking it with his Imagine Breaker, which surprises Ouma as he did not expect it to happen, though he is thankful that there was no unnecessary deaths as a result of his action. Touma's homework is destroyed however, and he demands Ouma to compensate for it, though he is unperturbed. Now with Touma confirming Ouma as a magician who is after the 103,000 grimoires within Index; he is forced to chase after Ouma who has kidnapped Index, and used an invisibility spell to escape the area. Ouma later takes a Index toa roof on a high building, to start his ritual after tying her up with a rope binding spell. Touma is forced to take chase, but is preoccupied by the restaurant employees wanting him to compensate for the damages done to the restaurant, slowing his progrees in finding her for hours.August 31, 8:15 PM. While preparing for his ritual, Ouma discovers that Index successfully untied some of her ropes, which impresses him. Index however, is determined to not yield to torture and not tell him any information, though Ouma says that he will not hurt her in any way and begins setting up the ritual location. Meanwhile, Touma has yet to find any leads towards finding Index, however, he bumps into Mikoto again, whose memories of the promise he kept with Etazali are still fresh and because of this she remains embarassed around him. However, Touma ignores her as he is too busy in finding Index, much to Mikoto's dismay.
August 31, 11:20 PM. Ouma has set up a replica of a Bon Odori stage as a ritual location to enhance the power of his bow, and allow him to read Index's mind and gaining access to one of the grimoires inside of her mind. Out of pure concern for Ouma, Index protests his decision, stating the fact that he would get hurt if someone other than her were to read a grimoire. However, Ouma knows very well what would happen, and is unbothered by this as he begins his spell to enter Index's mind. Meanwhile, Touma overhears their converstation by phone and discovers the building where Ouma is doing his ritual, as his ritual location appears brightly in the dark night. Seeing this, Touma decides to head there immediately.The ritual starts, and Ouma is just barely capable of taking in the grimoire from Index; as a result of the grimoire, he bleeds everywhere. The grimoire he is searching for is the Baopuzi, an ancient grimoire originating from China that is said to be able to cure any disease.
Ouma recounts on how he met a woman who has a cursed on her body and was fated to die, however, he has come to admire her accepting her cruel fate. Ouma however, denies to himself that he is not going through all this, just for the sake of saving that woman. However, Index argues that he is wrong; since the bow's power has been amplified his thoughts have also flowed into her, as such she knows how Ouma truly feels. Index states that Ouma has truly fallen in love with the woman in the hospital, and wanted to save her. However, since he has committed sins in order for her to be saved, Ouma convinced himself that he is not doing it for her sake as so she would not be the reason for him to commit those sins. Index then tells Ouma to not die if here if he wants to save her.At that moment Touma arrives and dispels Ouma's ritual location. Touma scuffles and argues a bit with Ouma (who faints afterwards), and is later awoken by Sphynx's scratches on his face, as punishment for destroying Touma's homework. Here, Touma convinces Ouma to have him take him to the woman he is in love with, and explains to him that his power is the Imagine Breaker and can negate any curse it comes into contact with. Ouma agrees, and they embark to the outside of Academy City.September 1, 12:00 midnight marks the end of the Yamisaka Ouma event.
Third Story: Misaka Clone 20001
August 31, 2:05 PM. In a certain part of Academy City, in the middle of the night, a certain white haired boy known as Accelerator is filling his shopping cart with an unusually excessive amount of black coffee cans. After, getting outside of the store, he is met by a group of delinquents who tries to attack him, though obviously to no avail, as they're attacks are immediately redirected by his power. He mentions to himself that since his defeat in the hands of Kamijou, he is no longer considered the strongest in Academy City, even though his powers still remain and that he is still a Level 5. As a consequence, delinquents have increased their attacks on him no matter how many times he puts them down. While leaving, he asks himself what exactly changed within himself.While walking, he passes by a certain apartment complex, and is annoyed by the noise created by two certain characters. He uses his vector powers to mute out any sound from him as he continues to walk alone. However, unbeknownst to him, he is being followed by someone. After a while, the person comes close enough to him for him to notice, and uses his vector powers to unmute sound.
Accelerator discovers that it is from a voice of a little girl, who calls herself Misaka, twice. Annoyed by her, Accelerator continues to walk along, ignoring the girl, though she continues to try and talk to him, telling him that she has been trying for him to notice her all this time. Suddenly, Accelerator remembers the name Misaka (much to the girl's delight), and demands the girl to remove her vestments and show her face to him. The girl naturally protests at this, however, Accelerator removes the cloth from the girl himself, and sees that the girl is completely naked, making her cry.The girl says that she is the 20001st clone to be produced for the Sisters Project, and says that her codename is Last Order. She continues by saying that since the experiment has been nullified, she was apparently released from her tank in the middle of the incubation process, as is the reason why she appears so small in comparison to the other clones. However, Accelerator only somewhat feigns interest in her plight. Last Order states that since Accelerator has connections with the researchers, she could use him to contact them for her. Accelerator gives an immediate response to her that he is not interested, which somewhat disappoints Last Order since she has nowhere else to go to now.Apparently feeling sorry for her, Accelerator lets Last Order follow him to his apartment building and pulls a couple of tricks to the very eager Last Order, much to her annoyance. When they get to his room, they discover that Accelerator's room has been trashed. Still uncaring and yet somewhat expecting of this, Accelerator lays down his purchases and proceeds to sleep on a relatively intact couch to rest. Worried, Last Order asks Accelerator if he should contact Anti-Skill or Judgment. However, Accelerator ignores her suggestions and asks what she should do since it is probably safer to rest outside than inside his room. Last Order however, insists that she stay in his room because she earnestly does not want be alone. Hearing this, Accelerator says that she could do whatever she wants. With that, Last Order, happy, goes to lie on Accelerator's surprisingly intact bed, and warns him not to touch her in the middle of the night, much to Accelerator's annoyance as he tells her to go to sleep already.Morning shines through the curtains of Accelerator's room, as he awakens from his slumber. Here, he discovers that Last Order is still in his room, and is hungry, asking Accelerator to cook some food. Accelerator ignores her and tries to go outside, which makes Last Order grow concerned. Accelerator states that he is not someone who cooks which disappoints Last Order.
Accelerator goes to a family restaurant with Last Order in tow. They later get into a casual conversation regarding his complexion and hair being of incredible pallor, to which Accelerator replies that it is due to his power reflecting the sunlight, as such, the body had no need to produce pigmentation. Accelerator later sees Amai Ao, and is suprised by his inexplicable presence. Accelerator questions Last Order about this, though she is uninterested of it and would rather eat first, much to Accelerator's consternation. Their conversation continues, however, it quickly turns serious, with Last Order asking questions about his feelings regarding being the strongest esper, and his position in the Level 6 Shift, grating his nerves.Accelerator questions her on how she could talk to him, the murderer of 10,000 plus clones. Here, Last Order states that since she is connected to all the clones, she of course knows. Last Order states that she was taught the value of being a clone, even if a single clone dies there's no way the entire Misaka network would disappear.
However, Last Order says that since every single Sister's life has it's own worth, then someone will cry if a Sister were to die, and that is the reason why there would be not a single Sister to have her life taken away again. Accelerator is affected after hearing this, however, Last Order continues to explain. Last Order says that without Accelerator the experiment would never have been proposed and that souls would have never have been injected into the lifeless Misaka clones, and thanks Accelerator for it. Thinking that Last Order is joking, Accelerator smirks and reminds her that he enjoyed killing the clones. However, Last Order counters by saying that Accelerator is lying, and says that Accelerator didn't want to go along with the experiment in the first place. Accelerator gets mad at her observation and says that the fact that he kept continuing with the experiment means that he thought nothing of the clones' lives. Last Order once again counters him and states that Accelerator tried to communicate with the clones many times, and cites that Accelerator talking to the clones was strange, as if he wanted to establish a link with them. Accelerator demands to know what made Last Order say that his insults was meant to establish a link with them. However, Last Order refutes his statement and says that indeed all the words he said to the clones were unreserved and were abusive, and actually diverges from wanting to establish contact with others. However, Last Order states that if one assumes that those words were used in order to get a negative response and the fact that all the insults were stated before an experiment began, then one can conclude that the words were used in order to scare the clones. Scared enough as so the clones will not want to fight anymore. Last Order continues by saying that the clones were unable to understand his intentions, though she asks him a hypothetical question on what he would do the moment the clones said that they did not want to fight anymore. The words hit Accelerator incredibly, but then, Last Order has been overcome with something. Last Order states that she is in a condition where her body is incomplete, as such her current condition. Accelerator tries to get a response from a now ill Last Order, however, in a daze, Last Order asks if Accelerator is going away because there is still food left on the table. Accelerator responds that he no longer feels like eating anymore, there, he leaves her coldly alone in the restaurant.
August 31, 4:11 PM. After walking for some time, he comes upon a research facility that started the experiment and massed produced the clones. Here, Accelerator decides to find a way to help Last Order, as his deems his powers are meant for destruction.When he comes into the building forcibly, he comes upon a young researcher woman there, Yoshikawa Kikyou, the only researcher left in the Level 6 Shift there, as the others have fleed and are in hiding to erase their relations with the failed experiment. After some minor pleasantries, Kikyou asks for some help in whatever she is doing, to which Accelerator refuses. Accelerator then asks for the manual for the Sisters, as well as an adjustment equipment, telling her not to ask him and treat it as a way to pay him back for the experiment for which he wasn't paid due to its cancellation. Kikyou utters a surprised tone, asking how Accelerator "knew" already, as she has detected only three hours ago and that she is still eliminating errors that is spreading due to a virus. Confused, Accelerator asks what she is on about. Kikyou explains to her that they have created a Last Order for the clones. Originally, there were only 20000 clones produced for the experiment, but an extra one was created secretly in on order to control the clones via a code traversing through the Misaka Network, which Last Order is at the center—an easily controllable young girl. Kikyou relates to Accelerator on how a week ago, Last Order broke from her incubation chamber and escaped as a self-defense mechanism, later discovering that a virus was inserted into her, which also made her subconsciously move away from any researcher. And due to the fact that the experiment is secret, Judgment and Anti-Skill could not be used in finding her. Kikyou tells Accelerator that the virus will activate on September the first at midnight, and after a preparatory time of ten minutes, the virus will initiate a command that will spread throughout the Misaka Network—to attack humans indiscriminately.
Seeing that the problem would have far reaching consequences for him, Accelerator becomes interested with Kikyou's plight. Kikyou reveals that the most likely suspect is not a warmonger nor a war merchant, but a fellow researcher named, Amai Ao, surprising Accelerator as he has seem him only a few hours ago. Kikyou states that Ao is the one who writes the personality files for the clones, making him the most likely suspect of the virus' creation. Accelerator asks how they would be able to stop the virus, and Kikyou states that she needs his help if he wishes not to have Last Order killed, the quickest way in stopping the virus, despite his argument that his power is to destroy, not to save. Kikyou states that he cannot force him to do anything and gives him two choices that he can do. The first is to find Amai Ao, and force him to stop the virus, the second is to retrieve Last Order. Kikyou shows the files for Amai Ao, as well as the pesonality files of Last Order contained within a small computer. Seeing this, Accelerator states that it would obvious what kind of choice he would make, and form there, chooses. Accelerator chooses to retrieve Last Order, taking her personality files, and leaves Kikyou to do an unlikely thing, save someone.August 31, 6:32 PM. As Kikyou prepares the data required to readjust Last Order, Accelerator arrives in the restaurant where he left Last Order alone. Accelerator is worried a little as there are many Anti-Skill in the area and that there an intruder has infiltrated Academy City, though he thinks is unrelated to Ao as the intruder has drawn too much attention to himself. As he arrives at the restaurant, Accelerator discovers that a burly man in a suit destroys and enters one of its windows, coming out invisible, and then bumping to a girl wearing a shrine maiden costume. Finally, Accelerator sees a familiar face, Kamijou Touma, the man who defeated him, going after the invisible man. Accelerator reacts accordingly but is too concerned with Last Order than to chase him. Upon entering, he questions around and discovers that Last Order is not there, and was taken, much to his shock, a man in a white coat and calling himself his relative took her—Amai Ao.August 31, 7:02 PM. Accelerator reports to Kikyou that Ao has taken Last Order, and has been her with a while now. This surprises the both of them, as they believe that the virus will activate even if Last Order is left alone. Kikyou hypothesis that outside organizations maybe willing to give him refuge, though she doubts that he has reached the outside according to her, as the authorities are on red alert due to an intruder (Yamasika Ouma)breaking into Academy City as well as a battle inside a restaurant occurring (Touma battling Ouma). Kikyou states that Ao is in a tight situation, being in debt, he has no supporters or friends that would aid him, as well as the fact that using his remaining money would lead to him, he is basically trapped in the district with the city on high alert. Seeing the hints, Accelerator cuts his talk with Kikyou, noting how Amai Ao's actions have become simplistic as he has been put in a tight corner like a rat, leaving for the research center where the First Production Plan first took place.
August 31, 7:27 PM. Predictably, Ao and Last Order is at the research center, but is unable to move it inside as it is locked, and he could not go anywhere. Amai Ao is worried that Last Order would die before the virus activate, as she has yet to finish her adjustments, and as each counts, Last Order's life is ticking away, and he has no way to extend her life as so the virus could activate. Suddenly, he discovers that Accelerator has discovered him. Scared out of wits, Amai Ao starts his car and uses it run Accelerator down, though he dispatches his efforts and him—falling unconsious. Securing Last Order, he calls Kikyou and asks her about the electrodes that are connected to her, to which she responds that it is used to monitor her life processes. Accelerator sees Last Order, and asks if they would be able to neutralize the virus with the equipment brought by Amai Ao, though Kikyou says that that is not possible, as they need specific equipment for such a thing. Accelerator then realizes that Kikyou is hurrying towards his location as it would be more efficient than Accelerator taking Last Order to Kikyou. She states that she has already anaylzed 80% of the virus, though she still needs to write a code to overwrite it. Suddenly, a voice can be heard from Last Order and starts to speak in gibberish and moving erratically, the computer that is monitoring Last Order's condition is showing several warning messages upon its screen. Hearing what is happening, Kikyou states that the virus code activating in midnight was a dummy to lead them off, and states that the virus is preparing to activate. With no choice, Kikyou tells Accelerator that the virus will take ten minutes to create a command that will be sent all throughout the Misaka Network, and that moment, Accelerator is the only who can stop it by eliminating Last Order. Accelerator is at a loss, he is angred that his power, once again, can only destroy and not save. Although, he is the strongest esper in Academy City, his power is only good for changing the direction of forces, and it can only be used for killing people. Then Accelerator realizes something: he can reverse the bioelectricity and blood flow of living things, then why not manipulate them. He has the personality files of Last Order from a week before her infection, as well as notebook-sized computer to read them. Here, Accelerator realizes that with using his powers to manipulate Last Order's electrical brain signals, he can delete the virus from her brain. Accelerator tells Kikyou about this, but she is adamant about doing it, and tells him that even if he could make himself a substitute for a Testament machine, the anti-virus code hasn't been completed yet, and that he fails not only would the clones die, other people will too. Accelerator is confident that he can do it, that he can erase the virus, and the can bring Last Order back to normal, though Accelerator laments on how he will have to erase their meeting, he decides to go through with it anyway, thinking that it would be better that if she forgets him, the monster known as Accelerator, the killer of her "Sisters" anyway.
August 31, 8:12 PM. Accelerator begins quickly reading the pre-infection personality files of Last Order, and memorizes it completely. After comparing it with the current information he has, Accelerator touches her head and begins the arduous effort of deleting the virus from her brain, taking up all his calculation ability all for that single effort of saving Last Order, before August 31, 8:13 comes to pass.Slowly but surely, Accelerator is able to erase the virus from Last Order, and the warning windows in the computer that is monitoring her are decreasing one by one. Accelerator becomes confident that he'll be able to make it in time, however, perhaps due to his mocking of fate, Amai Ao rises and points a gun on his head. With all his calculating ability concentrated at deleting the virus from Last Order, Accelerator has no way of defending himself via his reflection powers, and realizes that if he wishes to survive, he needs to let go of Last Order.
Despite this, Accelerator never lets go, and is shot by Amai Ao in the head, and he falls to the ground, mocking himself that if he could save someone, his life could change. But Accelerator has done what he needed to be done, and Last Order restarts her processes. Amai Ao sees this, and breaks down as his plans and his entire life is ruined as Last Order can no longer carry out Amai Ao's command. Seeing the failure of his operations, Ao points a gun at the unconscious Last Order. Angered that his fears were correct, Ao fires the hand gun. Suddenly, a hand emerges and manages to protect Last Order, reflecting the bullet back towards Ao's handgun, destroying it and injuring his hand—making it useless. Apparently, Accelerator has managed to survive the bullet using his powers after his hand was removed from Last Order. Here, Accelerator stands to protect Last Order from Amai Ao, with his head bloody. Ao mocks Accerelator acting like a hero, to which he admits that it is indeed unlike him, that he thinks it is naive for a person like him to be saving anyone. However, Accelerator states that Last Order has nothing to do with them, and that even though he is scum that is unworthy of being save, even though he has killed 10,000 Sisters doesn't mean he can let the other remaining Sisters to die. Accelerator acknowledges the hypocrisy of his words. However, Accelerator states that no matter how rotten they are, and no matter how many reasons they can come up with will never be enough to let them die. Wobbling, Accelerator tries to attack Ao, who manages to dodge him with incredible ease. However, Accelerator finally succumbs to his wounds and falls to the ground.
August 31, 8:38 PM. Seeing Accelerator fall to the ground, Ao reluctantly checks his body and concludes that he has indeed not moving and with his powers not working. With that, Ao uses his other gun with his other and points it at Accelerator, and tries to shoot him. However, he is shot instead by the timely arrival of Yoshikawa Kikyou. Ao awakens to Kikyou putting Last Order into an incubator, ensuring her survival. Ao draws his gun on her, to which she notices, and draws her own gun. She apologizes for her naïveté, as she did not shoot his vital spots, which would have spared him the suffering he has now. Kikyou points out that she tracked the location of the phone Accelerator used to communicate with her. She also tells that Accelerator will be fine, as she knows a certain frog-faced doctor. Ao tells her that he doesn't understand why Kikyou is doing this, as her personality is that of one who weighs the aspects between risk and opportunities. Kikyou tells Ao that she didn't really want to become a researcher as she is now and states that she wanted to be a kind simple school teacher. She continues by saying that she wanted to remember each and every face of her students, and listen to them when they have problems. Kikyou continues on with the things wish she had done but could not do, and states that she still has attachments to that dream apparently, and kneels to Ao's level, still pointing her gun at him, wanting to be on the same level as him. In the end, she still wanted to do something kind, not naive. Kikyou then points her gun on Ao's chest, with Ao doing it in kind. Kikyou asks Ao if he is afraid of dying alone, and states that if he has to take a life, choose hers instead of his. Ao says that Kikyou being kind doesn't suit her at all, and says what she has is just strength.August 31, 8:57 PM. marks the end of the Last Order event.
Yoshikawa Kikyou wakes up in a certain hospital after an operation conducted by the frog-faced doctor, the Heaven Canceller. He states that even though she was shot point blank with the military pistol, and in a vital artery, she survived because of the efforts of Accelerator, who although, unconscious, used his powers to control the flow of blood in her artery and not allow a single drop to spill, and allowed Heaven Canceller to operate on her artery with relative ease. He says that Accelerator does not look good, as his brain was damage, his verbal and calculation abilities will be affected, a necessity in using his powers, the very reason why he is called the strongest esper. Although Kikyou is saddened by this, Heaven Canceller says that she should not worry, he need only to use the troublesome thing that the experiment has left behind, the 10,000 clones, as so he could regain them using their network to perform calculations for him. Kikyou asks about Last Order, to which Heaven Canceller tells that she is fine and is with a girl that is similar to her, Misaka 10032. Before leaving, Heaven Canceller tells Kikyou that their little escapades have forced the higher-ups to permanently terminate the experiment, though they are letting her go after killing Amai Ao, she is basically unemployed. Hearing this Kikyou is disheartened that she can't live as a researcher anymore. The frog-faced doctor then tells her that there are other paths and begins to leave. However, Kikyou raises her voice and pleads to him to save Accelerator, and that if he was unable to, then she will never forgive him. The Heaven Canceller, responds to her rhetorically asking who she thinks he is talking to. He continues by saying that this is his battlefield, and that will return from it, bringing a patient who has been fighting for his life.Alone in the room, Kikyou remembers Accelerator's words regarding him: the man slaying 10,000 to saving the remaining ones. She smiles and says that Accelerator was able to do it because he tried.In the meanwhile, Touma with Ouma escapes to the outside of Academy City, after battling a few Anti-Skills on their way. Touma later cures the woman Ouma was in love with, and is later forced to return to Academy City with Ouma as an escort, forgetting Index completely after she was tied up by Ouma again and put back to Touma's dormitory, after making a commotion regarding what they are going to do.With the crippling of Accelerator, he is forced to ironically depend on the Sisters clones he was assigned to kill in the experiment in order to live properly. The events of the arc is the first step Accelerator took in his road to redemption, and that he has really changed from his old self. The events of the arc shows that Touma and Accelerator live in a small world, and foreshadows their eventual meeting. Yoshikawa Kikyou would later follow a new path, and become like a teacher to Accelerator and Last Order later in the series. Meanwhile, Etzali's refusal to carry out his mission would later force him into hiding into the dark side of Academy City to protect Mikoto in his own way, as Return of the Winged One would later try to send Xochitl to eliminate him for his betrayal. Touma's relying on Tsuchimikado Motoharu on taking care of Etzali, foreshadows their eventual relationship as members of GROUP. Touma and Etzali's conversation regarding the promise to protect Mikoto and her world, would forever influence Touma and Etzali's decisions concerning her for the rest of the series, while Mikoto continues to show affection for Touma afterwards.Finally, with Touma breaking out of Academy City to help Ouma would later complicate the operations of Anti-Skill and Judgment, as the events of the next arc takes place. Still, Touma does not finish his summer homework.
- A Day in the Limelight: For Mikoto, Index and Last Order.
- Arc Villain: Etzali and Ouma for Touma, and Amai Ao for Accelerator
- Blow You Away: The Azusayumi gives Ouma control over wind.
- Bullying a Dragon: Everybody who keeps attacking Accelerator, no matter how many times he effortlessly kicks their asses.
- Call-Back: Accelerator's adventure parallels Touma's from the Index arc. He runs afoul of bullies, then meets a mysterious and annoying girl, sees her naked, decides to save her, uses his powers to save her from something affecting her mind, and suffers brain damage for it.
- Entertainingly Wrong: The various Magic Side factions think the Touma is assembling an army to take over the world, just because he has so many powerful friends.
- Heel–Face Turn: Accelerator decides to do the right thing for a change.
- Hero of Another Story: Accelerator's adventure happens around the same time as Touma's.
- Incest Subtext: Tsuchimikado's sister notes that she likes incest fiction.
- Indirect Kiss: Touma and Mikoto accidentally mix up their hot dogs, leading Mikoto to freak out and spend some time trying to figure out which is which before giving up. Sharp-eyed viewers will note that they did end up switching.
- In Love with the Mark: The imposter was assigned to kill Touma and everyone close to him, but fell in love with Mikoto.
- Long List: Pierce Aogami's list of fetishes. Here's the light novel version:Pierce Aogami: Ha, you're too naïve, Kami-yan. I have a wide range of acceptance when it comes to women: not just heroines that fall from the sky, but also step sisters both younger and older, step mothers, step daughters, twins, widows, upperclassmen, underclassmen, classmates, female teachers, childhood friends, rich girls, blonde hair, black hair, brown hair, silver hair, long hair, semi-long hair, short hair, bobs, drill hair, straight hair, pigtails, ponytails, braided hair, wavy hair, messy hair, ahoges, sailor uniforms, blazer uniforms, PE uniforms, judo uniforms, archery uniforms, kindergarten teachers, nurses, maids, policewomen, shrine maidens, nuns, military officers, secretaries, lolis, shotas, tsunderes, cheerleaders, stewardesses, waitresses, white gothic, black gothic, china dresses, weak albinos, crazy day dreamers, girls with multiple personalities, dominatrices, princesses, kneesocks, garterbelts, crossdressing beauties, glasses, eyepatches, bandages, school swimsuits, one piece swimsuits, bikini swimsuits, slingshot swimsuits, ridiculous swimsuits, non-human girls, ghosts, animal ears, etc.- any female is within my area of acceptance.
- Skewed Priorities: Touma, when a guy is threatening you with a crossbow, now is not the time to be thinking about homework.
- Shooting Superman: Everybody keeps attacking Accelerator no matter how many times they see everything get reflected.
- The Unreveal: Whatever Touma said to the imposter at the end. It certainly made Mikoto blush, but we don't get to hear it.Mikoto: I know he doesn't mean anything by it. I know I'm nothing special. But he makes it really hard!
- Unusually Uninteresting Sight: Seriously, nobody in the restaurant bats an eyelash at Last Order wearing nothing but a blanket. Does the restaurant not have a "No Shirt, No Shoes, No Service" policy?
- Weirdness Censor: Even though several of the restaurant's staff and customers were looking at the scene when Ouma attacked, they somehow don't notice him and think Touma did it.