Index Librorum Prohibitorum/Chronology (Toaru Majutsu no Index)

Toaru Majutsu no Index
Being the main heroine of Toaru Majutsu no Index, Index has a large role in the events of the story, alongside Touma.

Index Arc
Index first meets Touma while hanging over his apartment balcony. She remarks about how she is very hungry and would be extremely grateful if he could give her some food. Index introduces herself as a nun of Necessarius and reveals that she is being pursued by magicians, who are after the grimoires that she has. At first, Touma is skeptical of the existence of magic, but is quickly convinced of it as he is able to destroy Index's "Walking Church" using his right hand. After a lengthy discussion, Index decides to leave Touma's house, as she doesn't want him to have to get involved, Touma goes to stop her and Index asks if he would be willing to "follow her into the depths of hell". Touma hesitates at this question and Index smiles to herself before walking out, forgetting her headdress while leaving. Because of this she later has to return to Touma's apartment to retrieve it, but is attacked by Kanzaki Kaori, who seriously injures her, albeit unintentionally.

Touma returns home in the evening to find Index covered in blood and unconscious outside his front door, he is then confronted by Stiyl Magnus and a battle ensues. During this battle against Stiyl, Index falls under John's Pen Mode. She aids Touma by telling him that Stiyl has placed runes all over the building to aid him. Touma quickly deduces a counter-measure and Stiyl is defeated. After Stiyl's defeat, Touma takes Index to Tsukuyomi Komoe's house, as she is not an esper and is therefore capable of performing the ritual to heal Index. Index, still under John's Pen Mode, finishes the healing ritual with Komoe by summoning a replica of an angel, while chanting. Afterwards, she falls unconscious.

When Touma later returns, Index tells him of the existence of the Church of Necessary Evil, also known as Necessarius. Later, she and Touma go to a bath together where she reveals that she has lost all of her memories from the previous year. For one reason or another she assumes that Touma is angry about this and runs away. Sometime afterwards she discovers that Touma has been beaten to unconsciousness (by Kanzaki Kaori) and that he has been asleep since. Stiyl and Kaori come to the apartment for her, but Index believes that they are after Touma, and she tries to defend him, only for them to leave without trouble, however, they give Touma a time limit, after which they say they will return.

While Index is resting, Touma discovers the hidden mark within her that could destroy her if her memories aren't periodically erased. Touma touches the seal with his right hand and causes John's Pen Mode to activate. Index then attacks Touma, as well as Kaori and Stiyl, who have made good on their promise and returned. Kaori and Stiyl discover that they've been tricked by their church into believing that they needed to erase her memories. With the help of Kaori and Stiyl, Touma is able to defeat John's pen (and in the process, destroys Tree Diagram accidentally) but at the cost of Touma losing his memories.

The next day, Index visits Touma in the hospital, where the 'frog-faced doctor' tells her that his memories have been completely erased. Even so, Index pleads with Touma to remember her in a heart-felt speech, asking him to recall the things that had happened between them recently and even telling him that she loves him. However Touma surprises her by stating that his memories were not really destroyed and that his right hand has fixed the problem. Index becomes upset at him for joking about such things and bites him, leaving shortly afterwards. However, it is revealed that Touma lied about his memories because he couldn't bear to see Index cry.

Deep Blood Arc
Index and Touma go to a restaurant with Tsuchimikado Motaharu and Aogami Pierce where they meet Himegami Aisa. Index argues with Aisa after the latter claims that she is a magician, however, their argument is cut short when Aisa's teachers come to pick her up. When walking home with Touma, she discovers an abandoned kitten and decides to take care of it, much to Touma's disapproval. The cat runs off and she tries to give chase. Suddenly, she notices someone applying a magic spell and decides to investigate, leaving Touma alone. When she returns to Touma's apartment, she is carrying the kitten with her and has decided to name it Sphynx. Touma disapproves at first, but eventually relents and allows Index to keep Sphynx, much to her delight.

After Touma again leaves, Index eats the pudding in Touma's refrigerator, when Touma calls her he scolds her for it but suddenly disregards it. Later when Index is taking a bath she remarks on how Touma became distracted about something when discussing the pudding and decides to go find him. Index later arrives at the Misawa Cram School where she meets Aureolus Izzard, and although he is familiar with her, she has no idea who he is as her memories of him were erased. Index is later struck unconscious and sleeps through the whole battle between Aureolus (who is planning to turn her into a Vampire) and Touma, somehow dreaming blissfully of Touma and complaining to him of her hunger.

Index, along with Aisa and Sphynx, later visits Touma in the hospital. She tells him that the church is going to take care of Aisa from now on. She proceeds to eat the apples that Stiyl gave to Touma before Sphynx wreaks havoc in Touma's hospital room.

Sisters Arc
Index and Aisa try to find ways to get rid of the fleas that are infesting Sphynx until Touma comes home along with Misaka 10032, much to the jealousy of Aisa and Index. Misaka 10032 helps get rid of the fleas on Sphynx using her electrical abilities and proceeds to lecture Touma on how he should disinfect the room against more fleas before leaving. Later on, Index and Aisa decide to go to Komoe's house for food, seeing as Touma has yet to return home. During their time there, Index helps herself to food as Komoe explains to both of them how esper abilities work using Personal Reality. Komoe uses a chocolate ball inside of a box to demonstrate this to Index, who is frustrated at not being able to figure out what the box holds.

In the anime adaptation, they later go to a public bath, drink milk and enjoy massage chairs. Komoe continues to explain to Index and Aisa about esper abilities and the strange occurrence of Level 0's in the city. She also inadvertently reveals that many "naughty" things happened with Touma in the past while blushing heavily, which irritates Index and Aisa.

After Touma's battle with Accelerator, Index once again visits him in his hospital room. She gets upset and bites him for trying to go it alone and not asking her for help. This is followed up with a loving hug, and Index tells him how she worries about him and that the next time he fights, he should come to her first. Index asks him what he fought for this time, and Touma says that he fought for himself.

Angel Fall Arc
At Komoe's insistence, Touma and Index go to the beach for a vacation to lay-low until the heat on them from the "higher-ups" dies down. Index shows off her new swimsuit to Touma and gives him a jellyfish to the face, confusing it for a hat. Index later becomes disappointed when she discovers that the arrival of Touma's parents has been delayed, but Touma calms her down.

When everyone's physical appearances are switched due to Angel Fall, Index switches appearances with Aogami Pierce, much to Touma's horror. For the most part of the arc, Index gets abused by Touma for looking like Aogami Pierce and coming on to him. When they return to normal, Index derides Touma for her abuse at his hands and punishes him as-per-usual by biting him.

Fake Date
While Touma is on his fake date with Mikoto, unbeknownst to Index, she is watching an anime called "Magical Powered Kanamin" intensively until Touma calls her, asking her if she is alright and informing her that a magician is in the city. She aids Touma by telling him the nature of the weapon the magician is using. Touma is cut-off from her before she can berate him again.

Last Order
Accelerator passes by Touma's dorm building while Index and Touma are arguing during the early hours of the morning. He blocks the sound out with his vector manipulating powers.

Yamisaka Ouma
Index and Touma go to a diner. Touma is working on his homework, and Index lectures him on it. She reveals that what he is studying is a veiled occult book and one of the 103,000 grimoires contained within her, before being attacked by Yamisaka Ouma. Despite Touma's efforts, she is kidnapped by Ouma.

During her captivity, it is revealed that Ouma is trying to pull a book from her that will cure any sort of ailment which he needs because of a woman he had fallen in love with. Index pleads with him to stop as the spell would be harmful to Ouma himself, all the while Touma hears the events unfolding using the cellphone he gave to Index.

Touma arrives just in time and stops the ceremony before any further damage could be done to Ouma. He proposes to remove the curse of the woman Ouma fell in love with using his right hand.

Kazakiri Hyouka Arc
Index follows Touma to school because she is worried that she will not get any lunch due to the refrigerator being empty and Touma not being back until the evening. She successfully finds Touma's classroom but is then swiftly told by Komoe to go home. Index meets a mysterious person named Kazakiri Hyouka, who helps her to use a vending machine. They become fast friends and Hyouka helps Index fit in by giving her a school gym uniform to wear. Their fun is cut short when Touma accidentally walks in on them getting changed. He is once again bitten. Index introduces Touma to Hyouka and tells him that they are friends, she also warns Hyouka of Touma's tendency to attract women before they are interrupted by Komoe. Hyouka then suddenly disappears. Index is later seen depressed because she believes that Touma is angry with her and that he hates her. Hyouka, however, consoles her and tells Index that Touma is angry because he cares about her and because Index is his friend. Touma finishes his classes and keeps his promise to go somewhere with Index, he also invites Hyouka to come along.

Index is very enthusiastic when they visit the underground mall. The three of them eat and also play games, and once again, Touma accidentally sees the girls changing their clothes, which Index promptly punishes him for. Their fun is put to an end when they are forced to evacuate due to a disturbance in the underground. They learn that it is the work a magician. Touma decides to protect everyone with his right hand, but Index is against this, believing it is her job to go against magicians. When they hear footsteps approaching, Index and Touma trip over each other. Index then meets Misaka Mikoto for the first time but due to both girls’ affections for Touma they do not get along very well. Both girls demand answers from Touma on what his exact relationship is with the other. Touma asks Kuroko about the situation and learns that there is a terrorist in the underground mall and that, as a member of Judgment and being a teleporter, it is her duty to evacuate civilians. Touma asks Kuroko a favor- to teleport Index and Hyouka away but Index disagrees because it would mean Mikoto being left alone with Touma. Touma then asks Kuroko to teleport Hyouka and Mikoto but Mikoto then disagrees since that would mean Index would be left alone with Touma. Because of this, Kuroko is prompted to teleport both Index and Mikoto away.

Later, outside, Mikoto and Index complain about the hot weather. There, Mikoto asks Index why she is wearing a habit in such heat and then asks why her garment is secured with safety-pins, to which Index replies that she doesn't want to remember how it got ruined. Suddenly, Sphynx runs away and prompts Index to give chase, leaving Mikoto behind. However, Index comes face-to-face with the golem of Sherry Cromwell, whose target is now Index. Even though Index cannot perform magic, she is successful in holding back the golem by intercepting the commands given by Sherry to the golem using the safety pins from her clothing. However, the golem begins to act on its own and begins moving automatically, making Index's situation grim as she can no longer disrupt the golem's movements. Index is saved by Hyouka who reveals to Index that she is not really a human and states that "only monsters should fight other monsters". However, even with Hyouka's vast amount of power she is unable to hold-off the golem, and the two girls are eventually saved by Touma who finally destroys it for good.

Index later confronts Hyouka about her not being human and hugs her, confirming to Hyouka on Touma's statements that she is still human regardless of what she believes herself to be. After a talk about the untrue nature of Touma's powers, both she and Hyouka conclude that Touma's power can't be classified as magic or esper. Index then says her farewells to Hyouka as she returns to the Imaginary Number Sector. She tells Index that she will always be at her side, even if Index can't see her and promises to meet Index again one day before fading away.

Orsola Aquinas Rescue Arc
At the begin she is talking with Tsuchimikado Maika, showing her dissatisfaction that without Touma on home the thing gets boring and asks Maika why she isn't at her school, then thinks if she becomes a maid she can go with Touma at his school with Maika replying that being a top-class maid isn't easy. Suddenly, Stiyl Magnus appears simulating an abduction in order to force Touma to get out of Academy City.

Meanwhile Index, staying at Hakumeiza, discusses with Stiyl about the situation concerning the Amakusa Christians and the grimoire named Liber AL vel Legis with the the first suspected to have kidnapped Orsola Aquinas and the Book of the Law to achieve ultimate power. Then, Roman Catholic Church assault team leader, Agnese Sanctis, arrives to join the talk.

Soon as Touma arrives at Hakumeiza along with Orsola Aquinas, the latter is kidnapped once again by the Amakusa Church. But Index suggest there is no need to hurry, as Index judges that Agnese still has little information regarding the Amakusa and suggests that they might use "miniaturized pilgrimage"—a magical transportation technique based on a certain map—to escape their pursuers. Despite this, Index assures that it can only be done at midnight, meaning that they still have four hours to prepare. Meanwhile, she uses the GPS function in Touma's phone to plot the location of the nearest portal. Index warns Agnese about the possibility of escape once the portal activates at midnight, and Agnese responds by reminding them to flee the scene when they fail to retrieve Orsola by five minutes before midnight. Agnese's forces and her group along with Touma and Stiyl go their separate ways.

For the meantime, they can only rest until the time comes.

Tree Diagram Remnant Arc
Index is often seen with Touma during this arc, she first appears with Touma wondering about the weather and how it was inaccurate. She later reappears when Misaka 10032 decided to ask Touma for help to stop the Awaki Musujime. Index is last seen with Touma in the hospital in the aftermath of the arc, where she lectures Touma of trying to act cool even though he didn't resolve anything (since Accelerator destroyed the Remnant as well as beating up Awaki).

Daihaisei Festival Arc
Index wonders around the city looking for Touma, eventually coming to the first event and watching it with Mikoto. She later meets with Komoe, who convinces her to put on a cheer-leading outfit. Unfortunately, Touma walks in as she was getting her underwear on. Naturally, she tries to bite him, only to miss and kiss him on the cheek, which causes her to become frozen with embarrassment. She is kept in the dark about Oriana Thompson as it would put her in great danger, which she wasn't happy about at the end of the arc. Later, she visits Aisa at the hospital, and when Aisa said that it would be better for everyone if she wasn't around, Index tells her otherwise, that she was a dear friend to both her and Touma.

La Regina del Mare Adriatico Arc
Index joins Touma for a short vacation to Northern Italy. The two finally arrive in Italy and Touma is trying to find the hotel they'd be staying at. Index shares a little bit of Italian history with Touma which makes him surprised that she knows things outside of magic due to the grimoires inside her head. This however upsets Index and was on the verge of biting him but she stopped because she wants to have a good time, but Touma with his usual poor choice of words further infuriates her prompting the annual punishment that he's accustomed too. Later Touma loses Index because she's too busy looking at the food stalls and restaurants in the area. Index is later found by Orsola Aquinas and takes her to her house where the Amakusa Christians are helping her move.

At Orsola's apartment Index is carrying a box of gelato and Touma berates her for separating from him and getting lost but she doesn't listen. Orsola asks Touma and Index to help clean the apartment with her and they both agree too, during the cleaning Index and Orsola ends up getting dusty so they decide to take a quick shower to clean their skins. Touma on the other hand is too busy trying to fight the temptation of walking in and avoid getting bitten by Index, during that time he hears a noise from another room and he goes to investigate it. It was there that both Index and Orsola come out of the bathroom naked and it turns out that the noise that Touma heard came from separate bathroom that Orsola and Index were using respectively. Touma tells the obviously embarrassed Index that he has no intention or interest at peeking at her naked body but Index takes his comment as an insult resulting in her giving him the usual punishment. Soon after, Orsola begins to move her luggage as she prepares to leave for England, when an assassination attempt happened, where a man wearing Roman Catholic Robes tried to kill Orsola but failed due to Touma. Taking a bizarre twist, the two fall into a river only to land on some large ice-like ship that was submerged before, and it sped off towards the sea with Orsola and Touma aboard, leaving Index behind.

Index later gets help from the Amakusa Christians, who later fish out Touma, Orsola, Lucia, and Angelene out of the water after the ice ship they were on was attacked by the other ice ships. Back on land, the Amakusas are eating dinner at Orsolas house alongside Touma, Index, and the two nuns, before proceeding to plans to rescue Agnese. Based on the information from Angelene and Lucia, the fleet is led by Bishop Biagio Busoni, and the purpose of Queen of the Adriatic Sea (the name of the fleet of similar ice shops) was to cast a spell that would destroy Venezia, the land as well as the pieces of its culture around the world, which required Agnese. Yet the effects of using her to cast the spell would render her to lose her mind, something Touma refuses to let happen. Humorously, Itsuwa offers Touma a napkin during the dinner, causing Index to be somewhat jealous of the seemingly closeness between the two. Moving on, the battle plan was to create a massive amount of paper ships, and use them as unmanned suicide bombers to distract the fleet while Touma and the others board the ship stealthily. The fleet notices this plan, and opens fire on a ship that was submerged below them, only to find out the submerged ship was a decoy, and Touma and the rest of them were aboard one of the suicide ships that flew towards them.

Touma, Index, and Orsola get on the main ship of the fleet where Agnese is being held, and after being split up and having to off thirty ice golems. Index later manages to get rid or escape from the ice golems, and is later reunited with Touma in an Italian hospital. They are then forced to return to Academy City after a single day in Italy, via a Supersonic Passenger Plane. Both Touma and Index would later have a bad impression on the plane.

Academy City Invasion Arc
August 31.

Lying on the floor of Touma's room and complaining of hunger, Index makes her displeasure known. Touma tells her the menu will be soumen and noodles, but she starts to complain about that too. Then, when Tsuchimikado calls them to share the food Maika has just made for him, she rushes to Tsuchimikado's room along with Touma. Touma and Index are then seen to devour the food.

Later, Index tries to look for Touma in the city but ends up becoming hungry. Accelerator later finds her, not knowing her connection with Touma, and even treats her with food - costing him all of his pocket money. They separate as Index spots Touma amongst a crowd and runs towards him, just as Last Order runs to Accelerator. She later berates Touma and then realizes that she has yet to return the tissue pack that the stranger she met, Accelerator, gave to her, leading her to go out on her own to find him, much to Touma's chagrin.

Index later comes upon Accelerator again while he is being beat up by Kihara Amata and surrounded by Hound Dogs, what's worse is that Vento of the Front's invasion of Academy City had just taken place. Distracted by Index's arrival, Accelerator uses the opportunity to allow him and Index to escape using one of the Hound Dog's vans. Amata tries to attack them with rocket launcher but is interrupted by Vento of the Front's arrival, whom wants to kill Index as well. Accelerator, considering Index dead weight, decides to drop Index off at the hospital where Heaven Canceller works, misleading her into thinking he needed a replacement battery for his choker electrode and having her fetch it (no replacement exists). There, she informs Heaven Canceller of what Accelerator told her and later falls asleep while waiting.

She is not seen again until after Kazakiri Hyouka is transformed into Fuse KAZAKIRI, forcing her outside as she recognizes her wings of light from the distance. Mikoto tries to stop her, at which point they are then reunited with Kamijou Touma. Index pleads to Touma not to destroy Hyouka, the angel he was going to stop, surprising her. Mikoto asks what that thing is to them and Index tells Mikoto that it's a friend and that they are on their way to rescue her. A few Hound Dog members spot and attack the three, but Mikoto decides to stay behind and hold them off. With the penalty game still being active, Mikoto orders Touma to stay alive and help his friend, and although he's reluctant to leave her, he obeys Mikoto's command. While running, Index asks Touma why the streets are empty, to which Touma tells about Vento of the Front. Here, Index explains to Touma the intricacies of how her power works and how it makes people faint. Later, realizing that Hyouka becoming an angel is related to AIM, Touma then contacts Mikoto to have her help Index regarding the matter. Here, Touma and Index once again split ways, with Touma going directly to Hyouka while Index go to the core where the change was forced on Hyouka.

Index later comes upon the building where Last Order is being used as the core that allows Fuse KAZAKIRI to happen. There, she also finds both Amata and Accelerator fighting, to which Index tries to help Accelerator by throwing a phone at Amata, though he is unperturbed. However, Amata is completely preoccupied by Accelerator to do anything about Index. Index determines that Last Order is the core of Kazakiri Hyouka's angelic form and compares the manifestation of Fuse=KAZAKIRI as forcing telesma into a container with human form, similar to what the Hermetic Order of the Golden Dawn used to do. She asks Mikoto (who is still fighting the Hound Dogs) regarding science side topics such as the Brain-wave networks as well as the AIM Diffusion field in Academy City. Index determines through their combined knowledge that Last Order's mind is being restrained in order for her to become the core of the mysterious power that the city has (AIM diffusion field) and to distort it to create an angel.

With this Index need only to remove the knot that is restraining Last Order's mind so to speak. Index concludes that a song would be the apt choice, as a song's rhythm, pitch and musical intervals can create multiple interactions with the mind and incite a multitude of emotions from a person. With this she could free Last Order from the shackles that restrain her mind, and save Hyouka and all of Academy City.

At the same time as this, Accelerator, in the brink of death, sprouts black wings and finally defeats Kihara Amata. With Index singing her Aria for Last Order, she fulfills her mission as after Touma's confrontation with Acqua of the Back, Hyouka's wings start slowly disappearing one-by-one. Index leaves Accelerator to call help for him, but not before stating that the black wings that appeared were similar to telesma.

Index later meets up with Hyouka after the end of the arc just before she disappears again.

Acqua of the Back Arc
Index is initially distressed that Touma has brought home yet another girl, however Itsuwa could quickly gain Index's heart using her excellent culinary skills. Touma, however; inspired by Itsuwa's usefulness when it comes to house work, removes her from being near Itsuwa as she was bothering her, and profusely requests the technologically challenged Index to clean the house bathtub heater (an electrical heater), Index used the knowledge of "detergent is what makes everything clean" and stuffed detergent inside the machine, effectively ruining the device. Afterwards, Index goes with Itsuwa and Touma to the Spa Resort Serene Springs, where she meets Misaka Mikoto and has a little quick exchange until Mikoto faints from overusing the bath. Later, after Kamijou Touma is injured by Acqua's attack, Index stays next to Touma after he is interned in the hospital. At the behest of Touma, Itsuwa kept the actual events of this arc as a secret to Index; and as such she didn't know who Touma was actually fighting until the very end, a fact that she used to scold Touma; along with his night time escapade from the hospital.

After the end of the battle against Acqua of the Back, Itsuwa is by Touma's side. Touma awakes to find her. She tells Touma that it is only normal for him to be unable to move after all that he had went through. Here, Itsuwa says that Aqua of the Back is still alive and retreated, as well as there being no casualties in the Amakusa or even among civilians. Touma then shows his nonchalance regarding the matter, saying that it was amazing that they managed to beat him, a member of God's Right Seat and a Saint. Itsuwa is surprised by this from someone who contributed the most, despite her being the key to his defeat using the Saint Destroyer, as they have not only beaten him but did not have a single casualty. Touma tries to get out of bed again, needing to go to school, but Itsuwa stops him by pushing him down and making her face close to his, making her blush. Suddenly, Index comes around, angry at him for having Itsuwa sit beside him instead of her as well as not yet apologizing for leaving the hospital on his own. Itsuwa joins the fray, asking why he ran over to where Acqua of the Back was despite his condition. Hearing Acqua of the Back's name, Index becomes even angrier at Touma for facing such a powerful foe without consulting her for help. Needless to say, Touma is distraught over their double team. Kaori then arrives, after much prodding by Motoharu, dress in the fallen ero angel maid outfit, barging into Touma's room, where he sees his "third angel" (referring to Kaori in her outfit) after Misha Kreutzev and Kazakiri Hyouka, though he is referred to as feeling fear upon seeing it from that point onward.

In the epilogue Fiamma of the Right states his intention of going after Index.

British Royal Family Arc
When Touma returns to the dorm after his school day finished, he and Index try to enjoy their evening before dinner trying out Touma's kotatsu. Touma later gets a call from Motoharu that he and Index need to go to England without explaining anything, and knocks them out using knock-out gas. The both of them as well as Sphynx, are taken to the airport with Touma's money stolen by Motoharu and exchanging it with British Pounds. With it being too late to board the last bus and train, as well as the banks being closed preventing Touma from changing his money back to Japanese Yen, Touma is forced to take Motoharu's offer. After waking up Index and Sphynx he explains the situation to Index, and later had her change into normal clothes. Index notes that though that they are going back to her city of birth, she doesn't really feel like it is her birthplace as she has no memories from before about a year ago. Here, Touma discovers for the first time since his own memory loss that Index too has lost her memories. They later find out that Motoharu has made preparations for them to board Academy City's supersonic passenger plane, much to their horror. Seeing this, Index and Touma decide to board on a commercial flight—Sky Bus 365. Only Sphynx boarded the intended supersonic passenger plane and arrives in London before both of them.

Much of the flight has Index wondering about their food as she hasn't eaten yet, much to Touma's consternation. They are later involved in a terrorist incident, and later becomes personal to Touma after one of them tried to silence Index after she discovered him by strangling her, he becomes enraged at the captain and becomes involved in taking down the two terrorists.

After arriving in Buckingham Palace's heliport, Touma and Index enters the palace after Kaori's explanation that Touma need not worry about destroying anything magical in the palace with his Imagine Breaker. Despite this, they are still hungry as they are greeted by Knight Leader. After Touma tells him that Index is hungry, they are given scones by a maid, at which point, after discovering it is free, they gorge themselves with it. The Knight Leader, shocked at the display and the fact that they are in a hurry, asks Kaori if she can draw her sword to persuade them, to which Kaori does something much quicker, punching Touma in the stomach and dragging Index by the hand. Knight Leader later tells them that they are gathered here to discuss the recent Eurotunnel explosion, which was actually a bombing and magic is involved. They later meet Elizard and her exuberant behavior, after Knight Leader scolded her for being unprepared for the meeting. After Touma notices the Curtana Second on Elizard's person, they start a lecture regarding the purpose and power of the sword and its connection to the history of the United Kingdom. The Eurotunnel bombing meeting in Buckingham Palace is conducted afterwards, Touma is one of the least vocal of the group that have gathered there, though is still able to speak more than even Villian. He opens up on how he thinks the meeting has something to do with Sky Bus 365 as the terrorists were French, which later leads to the discussion on the growing suspicions of the country regarding France. Meanwhile, Elizard asks Index to analyze the papers she has regarding the magic that was used to interfere with the illusion cast by Necessarius on Sky Bus 365, leading Index to say that it was Norse magic and that the magician is a girl.

When it was time for Index and Touma to split ways, with the former going to Folkestone in order to go to the Eurotunnel to analyze the magic there, Carissa tells Touma he can't follow. She says that Touma's Imagine Breaker may interfere with the investigation. Index and Kaori allays her concerns and tells him that he really doesn't need to do anything, with Elizard saying that he can do anything he wants until the situation is resolved. Touma, however is insistent in helping to keep England's peace, forcing them to acquiesce to his request.

British Halloween
As the British Halloween takes place, Index is accompanied by Carissa and Knight Leader in the Eurotunnel near the collapse portion of the tunnel. Here, Index determines that the magic used is of Roman Catholic origin and references French royalty's passing relation to it. Hearing Index's analysis that a spell related to the French royal family was used, Carissa now determines that the one at fault is a French Roman Catholic faction. Despite Index saying that the spell's used it doesn't necessarily mean that the current political power used it since the French monarchy has been ended, Carissa is adamant, pointing out that the brains behind the current political power in France have the knowledge of the historical kings of France and treasures from the royal palace. With a smile, Carissa congratulates Index for giving her the answer she wanted to hear, that France was at fault for the bombing, as otherwise she would have killed her, putting Index on guard. Knight Leader comes near and hands her the Curtana Original from the case.

Using Index's analysis as justification, now as the new sovereign of the country, Carissa orders the Knight Leader to have the Knights of England to force the military to send a destroyer to Dover Strait, and from there threaten Versailles, destroying it depending on France's answer. The Knight Leader asks if they should notify Academy City, their ally, to which Carissa's says to ignore them, threatening the connection that was established by Academy City and the Anglican Church. The Knight Leader asks if targeting Versailles is the best idea as the current political power of France is controlled in the shadows who have no permanent base, to which Carissa says that it is only because the greatest of them all is hiding in Versailles, and killing her would force the others out of hiding. Carissa orders the use of Bunker Cluster warheads. She says she will disregard the treaty that they signed to ban it with the nations of the EU as well as other unnecessary treaties. Carissa also states that she intends to cut America's economic backing to further her desire for the United Kingdom to become more independent from her neighbors. Knight Leader warns that isolating themselves after the Eurotunnel bombing and the hijacking straining the nation could make it worse. Carissa however says that all they need to do is remove the Roman Catholic Church's control from Europe, creating a structure that centered around England, solving the problems with the economy and resources, a society where England is needed by the rest of the world. Carissa comments that her mother's pacifism doesn't work in times of war and that they need to win the upcoming war without any cooperation and interference from others. Accepting, the Knight Leader begins preparations for the destroyer. Carissa comments on how she wishes that they have developed nuclear bombs, prompting the Knight Leader to say that they should use something that would not be harmful to people after the Palace of Versailles has been hit. Carissa laughs at this and says that they can send a warning beforehand as the woman they are after won't leave the palace even if they did. Carissa, still needing Index to legitimize their threat against France, then orders the Knight Leader to "put her to sleep". The Knight Leader then knocks Index out with a single punch.

Index is kept in a carriage unconscious during the Battle of Folkestone until she is rescued by Acqua of the Back. Touma later arrives and after a discussion with Acqua of the Back and encounter with Carissa, stays with her. Index later wakes up and both she and Touma are later found by Amakusa Christian scouts, and later bring them back to their temporary hideout in Folkestone, a large rescue seaplane. As it takes off for the London, Tatemiya Saiji and Kanzaki Kaori report on the current situation regarding Carissa and her frail relationship with the knights now that the Knight Leader has been defeated. They tell him of the reason for her returning to Buckingham Palace as so she can suppress the tremendous power of the Curtana Original, and that they need him, Index, and Villian to do a mission under the Buckingham Palace and force the Curtana Original to overload and weaken Carissa, allowing for the forces of the Anglican Church to mount a counterattack against her. With Index's instructions and Villian's driving, Touma's party easily bypasses the knight's magic after discovering that Carissa had London's security cameras deactivated. After coming near Buckingham Palace, the group disembarks on foot following Index's lead, eventually arriving at a subway station. With a little help from Mikoto and Villian's servants, Villian is able to use the spell against the barrier, which have been modified with the help of Index in order for her to chant it quickly, ending with Touma destroying it. With the branching railway open, the special car begins moving towards Buckingham Palace. Touma and the others later leave as Curtana is overloaded.

The group later rendezvous with the Anglican Church forces in the outskirts of London. During the "Last Supper", Index has her fill of food, even stealing from Angelene. She later meets a nun from the Anglican Church named Rachel, who says they used to play together, though Index has no recollection of her as her memories have been erased. Seeing that Index is still so cute, Rachel offers her food, as do others, eventually making Index say for the first time that she has had enough food.

In the Battle of Buckingham Palace, Index is separated from Touma, and is instead carried by Kanzaki Kaori during Carissa's counterattack on their assault using Curtana Original's dimensional debris. Index arrives after Kaori went on a short detour to save civilians from the debris, just in time to save Touma who was in dire straits facing Carissa. There, Kaori asks Index to analyze the Curtana Original, while she and the others fight Carissa. For much of the battle, Index continues to analyze the Curtana Original while as the same time assisting using her Spell Intercept. It is her combo with Villian that allowed them to give an actual blow on Carissa, who hitherto dominated the battle despite the numerical superiority of the Anglican Church forces. Despite this, Carissa orders the firing of a Bunker Cluster cruise missile on the palace. Thanks to Kaori's quick thinking, she is able to make a defensive barrier over their area, though not all of it is covered and some of the explosive shells get through, eventually destroying the palace itself. Index is not seen until later, after Elizard uses the Union Jack spiritual item and distributes the power of the Curtana Original to the citizens of the United Kingdom. Here, Index admires the skill of Elizard's magic, who uses her communication spell to have the people of the United Kingdom people in their own interpretations of the power of Curtana they are receiving in order for them to properly use them without discovering that it is magic. Index wonders if the purpose of her creation was to support Elizard, As Carissa's defense breaks down in the onslaught of the "heroes" and the forces that oppose her present due to the fact that she was trying to prevent power from her sword to be completely drained, an opening for Touma arrives after Index finally finishes analyzing the sword and uses Spell Intercept on it. Touma calls out to Acqua of the Back, and without a word, knew what Touma was planning. Acqua of the Back catapults Touma toward Carissa using his sword, Ascalon, and from there destroys the sword and then punches Carissa in the face.

When Fiamma of the Right appears to steal John's Pen remote control from the ruins of Buckingham Palace, he activates it as a demonstration, forcibly putting Index into John's Pen mode. He tries to have her attack Touma and Carissa, though finds out that it is damaged, due to its battle with Touma and damaging its "Collar". Though dismayed, Fiamma of the Right is unperturbed. He reveals he was after the knowledge of the 103,000 grimoires held within Index, something that the remote control allows him to access. Index later falls unconscious after Fiamma of the Right leaves. Elizard later takes Index's body and promises to heal her on their end, though warns Touma that so long as Fiamma of the Right has the remote Index is still in danger. The events of Fiamma of the Right's actions would later force Touma to go alone to hunt Fiamma of the Right down after asking Stiyl to keep a close watch on Index as he is privy to the ways of the Church.

World War III Arc
Index eventually learns of Touma's memory loss through Fiamma which causes her a great deal of pain. During her stay at the St. George Cathedral- the Necessarius headquarters, Index grows "Red Wings" and defeats Stiyl Magnus with ease, who tries to restrain her in vain. She succeeds in destroying the headquarters in the process.

After Touma defeats Fiamma and refuses to escape from the fortress, Index asks Touma why he didn't escape too. He told her that there were still a task to take care of. When she asked about his memory loss, he promises her that he will meet her again and apologize personally. He tells her to get Stiyl to contact him so he could control the fortress' decent, and he destroys the controller. After Touma disappears, Index asks Stiyl what happened to Touma, but no one can answer her question.