Daihasei Festival Arc (Index)

The Daihasei Festival Arc is a story arc in Toaru Majutsu no Index. It is September 19th, and the time has come for Academy City's annual Daihasei Festival, a sporting event that pits ability users from across the various schools of the city against one another in a series contests. For Kamijou Touma, this year's festivities have come with a twist as he finds himself having to foil a plot that could wreck the fragile balance between the worlds of science and magic.

The arc marks the 2nd time the Roman Catholic Church acts as the primary antagonist for Touma, it involves the church allowing Lidvia Lorenzetti to take over Academy City for the benefit of the church using the Croce di Pietro.

Increase of hostilities in the Magic side
With the destruction of their main fighting strengths: the Gregorian Chant and the Agnese Forces, as well as with the Amakusa Catholics and Orsola Aquinas joining the Anglican Church (due to the events of September 8), and with the balance of power gradually shifting to the Science Side, the Roman Catholic Church has become severely weakened enough to allow the Mardi Gras – Lidvia Lorenzetti – to set up the Croce di Pietro in Academy City and take it over in secrecy. With the church suceeding in taking control of Academy City, would cause the power balance to shift to the church's favor since Academy City is the center and the entirety of the science side.

Lidvia's reason being in ensuring the welfare of the world as she views the Science side is ursurping God's will, as well as her innate desire to conquer a difficult challenge, which is in this case taking over Academy City for the Roman Catholic Church and evangelizing it's inhabitants under it's dominion.

Oriana Thomson, an expert courier and master in eluding capture in the magic side, is later involved with the operation, under the belief that having the Roman Catholic Church control Academy City, would create an absolute standard concept regarding goodness, due to it being governed by the laws of one unifiying belief. Since the concept of good being dependent on a human's perspective towards it, which often cause tragedies since it becomes twisted due to the nature of humans. Oriana sides with the Roman Catholic Church since they are the most capable of achieving her goal, through the dominion of others.

Roman Catholic Church plans
The plan was for Lidvia Lorenzetti to activate the Croce di Pietro outside of Academy City during the Daihasei Festival because of the stressed security for the event, while Oriana Thomson acts as a decoy for any magicians trying to stop them. For the plan to work, they made use of Croce di Pietro's obscurity and created a ruse regarding a fake artifact known as the Stab Sword that could kill a Saint in one blow, with this they are able to keep any Saints allied with any opposing factions at bay during their plan. The church furthered this deceit by leaking false information that Oriana was hired by Lidvia as a courier to transport the sword into Academy City, to be received by an unknown party. They also made sure that they distance themselves from Lidvia for the plan to work, as so to not attract attention.

Conveniently, the Roman Catholic Church's planning on capturing Academy City, has stifled the efforts of outside magical factions in entering Academy City to stop the "delivery" because it is an enemy territory, and would constitute as an invasion to both the already troubled sides. This forces factions to resort to only those who have connections in Academy City to enter the city to stop them.

Reaction of other factions
The ruse works as the Anglican Church is led to believe that the Lidvia is working with Oriana on their own to deliver the Stab Sword in Academy City, with the church also suspecting that Nikolai Tolstoy of the Russian Orthodox Church is the recipient of the delivery. Because of the danger posed to the balance of the magic side by the Stab Sword, Laura Stuart contacts the General Supervisor of Academy City – Aleister – to help with the situation. Here, she reveales to Aleister the Stab Sword and its use, the relevant parties involved with the deal, and the place where the deal would made, Academy City. As a response to this, Aleister allows Laura to send out operatives who have friendly relations with Academy City (more likely because of Kamijou Touma), due to the volatile politics involved with sending out magicians to operate in Academy City, as many other factions would want to get involved in the operation themselves.

Prelude
As with the agreement, Stiyl Magnus is to meet with Tsuchimikado Motoharu to handle the deal with the Stab Sword as they are one of the few members of the Anglican Church that has friendly relations with Academy City, while Kanzaki Kaori is forced to go on standby due to the nature of the situation.

Meanwhile, Kamijou Touma has a bet with Misaka Mikoto, in which the student of the school which a lower score than the other is forced to do whatever the winner tells him or her to. Touma later competes and successfully wins a competition with his classmates, after seeing Tsukuyomi Komoe get insulted be a fellow teacher for her class' (Touma's class) poor academic performance. Meanwhile, Mikoto witnesses Touma's team's efforts in defeating their opponent with Index, and is actually worried at the prospect of losing to Touma.

After getting to a perverted incident with Fukiyose Seiri, who he sees naked; Touma later joins Index for a little snack, however, due to security issues Touma is only able to have Index eat after the next event he is, much to her frustration. Index decides to take her anger out on Touma, however, he is saved by the arrival of Mikoto who drags Touma away because he is the item that Mikoto requires for the Borrowed Item race that she is in. At the same time as this, Shirai Kuroko, still wheelchair-bound is with Uiharu Kazari, and sees Mikoto with Touma on a giant television screen, irritating her that he is with Mikoto.

Kamijou Touma's involvement
Touma later returns to the spot where he left Index, though he could not find her (since she was taken away by Komoe), however, while looking for her he discovers Stiyl and Motoharu talking and decides to investigate. Here, he discovers that a magician named Oriana Thomson was hired as a courier by Lidvia Lorenzetti of the Roman Catholic Church, and has infiltrated Academy City due to stressed securities, and is planning to deliver the Stab Sword to a recipient in Academy City. Stiyl and Motoharu explain to Touma why the magicians chose Academy City for the deliver, the reason why Kanzaki Kaori cannot be involved due to the nature of the spiritual tool being delivered. They also the reason that only magicians that have friendly relations with people from Academy City, such as Kamijou Touma can enter Academy City (under the excuse of simply visiting Touma), because sending out operatives from the magic side such as the Anglican Church into Academy City would attract other factions.

Motoharu later tells Touma on how the Stab Sword could kill a Saint, as well as the likely reason for the deal was to prepare for the war between the factions. Motoharu also explains to Touma on why he cannot involve Index into their mission, even though she would be quite useful for it. He states that due to the deal taking place, several other magic factions are observing the situation in the city using magic, since they are unable to intervene (for their own purposes) because the trade is happening in Academy City. Index is attributed by several magic organizations as the one to have settled (actually Touma) the magic side incidents happening occurring in the city, as her identity and prescence is much more noticeable to magicians, as such they could track the deal and most likely, Stiyl, Motoharu and Touma's operations against it using Index, and use that as an excuse to rush into Academy City.

Meanwhile, Index is fed by Komoe after being left alone by Touma, and later agrees to wear to try on a cheerleading uniform to try and cheer for Touma. Back with Touma, he meets up with Himegami Aisa and Tsuchimikado Maika, who directs him to Index's whereabouts. Touma goes into a botanical garden and finds Komoe and Index; much to Touma's misfortune, the latter is indecent (as she was changing into her cheerleading uniform) with Touma accidentally seeing her. Index tries to bite him out of anger, but fails and accidentally kisses Touma on the cheek, which embarasses her. To complicate things, Fukiyose Seiri arrives searching for Komoe for committee work, however, after seeing what Touma has gotten himself into she attacks him and later drags him away.

First Chase
While Touma is being dragged by Seiri, she comments on how he is somewhat restless and asks whether the festival is boring to him, worried that she is not doing enough as a committee member to make the festival more enjoyable. Touma denies that the festival is boring, still worried, Seiri demands Touma to tell her what's making him restless, though obviously Touma cannot tell her about the magic side. However, someone bumps into Touma which inadvertently pushes his face close to Seiri, much to her discomfort and later headbutts him. As a result, Touma later bumps into the chest of a blond woman wearing a poorly buttoned work uniform, carrying a large billboard covered in cloth. After being coerced by Seiri to not accept the woman's kiss as an apology, Touma shakes hands with the woman. Suddenly triggers Touma's Imagine Breaker and making him suspicious, she leaves quickly afterwards.

Touma pursues the suspicious woman while contacting Motoharu regarding the incident with the woman carrying the clothed billboard; he later tells Motoharu his location. The woman is Oriana Thomson who is aware that she is being followed by Touma, reports to Lidvia that one of the spells that they set-up was somehow negated. Though Lidvia is worried about this, she demands Oriana to perform a countermeasure, to which Oriana runs away from Touma to escape.

Touma tries to pursue her, though she nearly escapes his sights if not for the arrival of Motoharu and Stiyl, due to Touma sending his coordinates to Motoharu. With this, the three of them pursue Oriana after being identified by Touma, even then she is too slippery and has too much of a headstart for them to catch up to her. However, Oriana's path is interrupted by a crowd of people, because of this she is forced to take a turn and go into an Autobus Maintenance Terminal. Touma, Stiyl and Motoharu continue their pursuit of her into the terminal, however, they encounter various traps set up by Oriana using her magic. This compels them to be careful in their movements, even with Touma using his Imagine Breaker to cancel Oriana's traps. In a lull in their chase, Motoharu asks Stiyl to apply his runes in the terminal and to be on standby. Motoharu and Touma continue to pursue Oriana before she gets away, plowing their way through her traps, however, because of this Oriana is able to put enough distance between them to lose their sights on her, and as such Oriana escapes from them. While escaping, Oriana bumps into students carrying a large pole for the ball tossing competition, and decides to use it as a means to draw Touma and the others away.

After finding one of Oriana's flashcards she used for magic, Motoharu creates a magic array in order – the All-around Reality Array, which works in a three kilometer radius – for them to find Oriana using the flashcard as a medium, using Stiyl as the magician to perform it. However, while using the searching spell, Oriana notices Stiyl and uses a counterspell on him. The counterspell causes Stiyl to be experience excruciating pain, this forces Touma to use his Imagine Breaker negate it. While recovering Stiyl, Motoharu and Touma discuss on how Oriana is able to create complicated magical spells, and how she was able to make use of Stiyl's lifeforce to create a counterspell, with this, Stiyl would experience intense pain if ever he uses magic. In the original light novel, Touma, Stiyl, and Motoharu expand their discussion to that of magic arrays in general, how they are similar to grimoires, and how it relates to Oriana's type of magic.

The group decides to destroy the Oriana's counterspell Shorthand Origina las top priority, to enable Stiyl to use magic again. However, to be able to do is they needed to find it first, using a Divination Circle array that reacts to counterspell. This basically forces Stiyl to use magic and experience pain again as so the counterspell would react to Stiyl's lifeforce in order for the Divination Circle to locate the counterspell Shorthand Original. Though reluctant in letting Stiyl getting hurt again, and after hearing Motoharu's arguments, Touma allows Stiyl to use magic in order for the counterspell to react. Stiyl later declares his displeasure with Touma being here with them instead being with Index, with this, Stiyl begins using magic.

Ball Tossing Competition Crisis
The spell works, though at the price of making Stiyl temporarily disabled. This angers Touma after seeing Motoharu's apathetic nature towards Stiyl's condition, however, he relents after seeing Motoharu himself bleeding after using magic to activate the Divination Circle. While trying to find the likely location of Oriana's Shorthand, they discover to their horror that it has been set-up in a middleschool.

With Stiyl incapacitated, Motoharu set-up a All-around reality array for him to use when they finished destroying Oriana's counterspell Shorthand and leave him in the terminal. Meanwhile, Touma and Motoharu race to get to the middleschool before the match starts, with the threat of the counterspell hurting civilians, Touma and Motoharu are forced to infiltrate the middleschool by disguising themselves. When they enter the grounds, they soon discover that the middle school is forced to compete against Tokiwadai Middle School with Misaka Mikoto already seeing Touma present. They are forced to be extra careful as not to get caught in the crossfire during the competition, as they search for the poles used in the competition, which Motoharu deduces to be the most likely place the counterspell Shorthand has been set-up.

The match starts and chaos ensues on both sides while Touma and Motoharu check the poles one-by-one for the Shorthand. However, due to the carelessness of the competitors of the other middleschool, one pole begins to fall which forces Touma and Motoharu to act quickly, in the fear that the pole may have the counterspell Shorthand. With the help of Motoharu, Touma is able to save a girl from Tokiwadai from the pole's path, and instead puts him in danger. However, he is saved by Mikoto's intervention, who used her Railgun to move the pole. She appears before Touma and demands to know why he is here while attacking him if with here electricity, though obviously to no avail. However, their argument is interrupted after Touma sees Mikoto trying to lean on a pole, which has a piece of paper stuck on it. Touma suspicious of this, tells Mikoto to move away from the pole though Mikoto does not understand, with Touma unwilling to divulge information regarding the magic side to explain to her. She later begins to misunderstand Touma's intentions even more after negating an attack from a middleschooler, she blushes and becomes restless because of this which Touma sees as a sign that she has become affected by the counterspell Shorthand after touching it. This forces Touma to dash forward towards her and make her lie on the ground, as so he can check on her condition. Mikoto becomes even more reddened because of this and freezes herself because of him, to which Touma sees as a sign of the counterspell and calls Motoharu over to the pole where the paper was placed.

However, this was a mistake, as he discovers that the piece of paper is not the Shorthand. Shortly afterwards, Fukiyose Seiri arrives and stops the match, demanding to know why Touma is in the grounds while leaning on a pole. Suddenly, Seiri is blown down by an unknown force and collapses to the ground. The pole had the Shorthand which reacted to Seiri touching it; Motoharu arrives and tells Touma to use Imagine Breaker on Seiri quickly as she is not a magician and is much more vulnerable. Seiri is later taken away by parademics and is later sent to the Heaven Canceler's hospital. Meanwhile, Touma strikes the pole with his right first where the Shorthand was placed, and declares that he will destroy Oriana's illusions with it.

Trivia

 * This arc would mark the first time an arc covers two novels.