Orsola Aquinas Rescue Arc

The Orsola Aquinas Rescue Arc is a major story arc in Toaru Majutsu no Index storyline. It focuses on the rescue of the title character of the arc, Orsola Aquinas, a member of the Roman Catholic Church who has found a way to decipher the mysterious Book of the Law, a grimoire that is said to hold great power. The arc marks the first time Touma battle against the Roman Catholic Church, as well as the first as the first time two different Christian sects – Anglican Church (specifically Necessarius) and the Roman Catholic Church (specifically Agnese Forces) – come into conflict.

Political Strife in the Magic Side
After the destruction of one of the Roman Catholic Church's holy artifacts, the Gregorian Chant, during the Deep Blood Arc, the church's power has been weakend considerably, enough for them to have a power struggle within their own ranks. As the Roman Catholic Church is still the largest and most powerful Christian sect in the world, and desired to maintain it's dominance; because of this, after discovering that Orsola Aquinas can decipher the Book of the Law, a powerful grimoire that is said to end the age of the religion based on the cross (Christianity), they created an elaborate plan to capture her (and later execute her in secrecy), by fabricating the story that the Book of the Law that was being transported by Japan for exhibition and was stolen by the Amakusa Catholics, and also kidnapped Orsola Aquinas. Even, Stiyl Magnus thinks it is a rational decision for the Amakusa Catholics to regain power using the Book of the Law after Kaori left them. The Roman Catholics sent out one of their main fighting strengths, Agnese Forces, which consists of 250 battle nuns, to execute the mission.

The Anglican Church however, was allowed to aid the Roman Catholic Church's in their effort to capture her Orsola Aquinas, at the insistence of Archbishop Laura Stuart. Kanzaki Kaori, a Saint and a member of Necessarius, has recently went missing during the incident, and is presumed that she will act on her own accord in order to aid her former comrades, the Amakusa Catholics, as such problems will definitely arise if a Saint would intervene, as such the Archbishop wants to defuse the situation before Kaori does anything troublesome. Laura Stuart sends out Stiyl Magnus to retrieve Index and her guardian, Kamijou Touma to aid with the mission of rescuing Orsola Aquinas with the Roman Catholic Forces. Laura also instructs Stiyl to give a crucifix to Orsola Aquinas when the opportunity arises.

Orsola Aquinas

 * Main article: Orsola Aquinas

Orsola Aquinas is a Roman Catholic Church nun, who is famed for spreading the word of the gospel in three pagan countries and has a church named after her. She has been reported to have found a way to decipher the Book of the Law (a book not even Index nor Sherry Cromwell could decode), using incomplete copies of the book. The reason being, is that she wants to find a way to destroy grimoires as she sees that nothing good can truly be gained from the power of grimoires.

Because of her capability of deciphering the Book of the Law, Orsola was targetted by the Roman Catholic Church, and was forced to seek the protection of the Amakusa Catholics.

Kanzaki Kaori

 * Main article: Kanzaki Kaori

After hearing of the reports of the Roman Catholic Church, that the Amakusa Catholics have stolen the Book of the Law and kidnapped Orsola Aquinas. Kaori returns to Japan, to observe if the church she has left long ago, has truly wavered from the path that she guided them on when she was still their leader.

Other Factions
Meanwhile, several members of the Knights of England swam from England all the way to Japan, in an effort to solve the situation on their own due to political turmoil between the Knights and the Church, by disobeying the orders of Laura Stuart to assist the retrieval of Orsola Aquinas and the Book of the Law and instead simply kill all the Amakusa Catholics, regardless of the relationship it has with the Church or the Roman Catholics, as it does not affect Britain. However, they are later attacked by Kanzaki Kaori and were easily decimated in a matter of seconds.

Tsuchimikado Motoharu, a operative and a spy for various organizations, was mobilized as well by an unknown faction to retrieve the Book of the Law when the Roman Catholic Church and the Amakusa Catholics are to fight.

Prelude
Before the events of the arc took place, Orsola Aquinas escaped from the Amakusa Catholics during a confrontation with the Roman Catholic Church (no casualties were reported in both sides), believing that they had ulterior motives (specifically to seek the power of the Book of the Law) instead of just protecting her. She later enters Eastern Tokyo, to seek refuge in Academy City, an enemy of the Magic Side.

Gathering of the Factions
As ordered by Laura Stuart, Stiyl Magnus went to Academy City and 'kidnapped' Index as an excuse for her guardian, Kamijou Touma to get involved as well since he is part of the Science side, though according to Index this unneccessary as Touma would come to his aid even if he did not ask. As instructed by Stiyl, Touma leaves Academy City to rendezvous with him and Index in Hakumeiza. They later meet up with the leader of the Roman Catholic Church faction assigned for this mission, Agnese Sanctis. Here, they discuss the situation regarding the Amakusa Catholics, while waiting for Touma to arrive.

Kamijou Touma meets Orsola Aquinas at a bus stop en route to the rendezvous point, not knowing of her significance. Here, he convinces her that she cannot go in to Academy City using buses, as well as the fact that she has no entry permit. After, Orsola tells Touma him that she is being hunted, he decides that it would be wise to bring her to Index. After arriving at Hakumeiza, Touma discovers the reason for why he and Index were called upon – to help aid the Roman Catholic Church secure the Book of the Law and Orsola Aquinas. Stiyl says that Touma has fulfilled his purpose, as he has brought Orsola Aquinas to them and can now hand her over to the Roman Catholic Church, though irritates Touma a little for his careless disregard for his well-being. Orsola's reaction to this is negative, as she slightly trembles, though Touma, Stiyl and Index are unable to understand why.

However, they are later disturbed by the arrival of the Amakusa Catholics, who abduct Orsola Aquinas from beneath her feet. Touma and Stiyl try to retaliate and get her back they are too late, as they have already escaped in the sewers.

Roman Catholic Side
After the kidnapping of Orsola Aquinas by the Amakusa Catholics, Agnese gathered her forces at Hakumeiza, analyzing the current situation with the Amakusa Catholics, and has set up a perimeter with a radius of 10 kilometers to detect them, thinning their forces. Though such a large perimeter was later unneeded; using the vast knowledge of Index, specifically her knowledge on the Amakusa Catholics, and their use of Dai Nihon Enkai Yochi Zenzu portals, she was able to pin-point the most probable location where the Amakusa Catholics are and when they would be able to use the portal, which is at the Parallel Sweets Park. With a large gap between the current time before their mobilization against the Amakusa, the Agnese Forces prepare their weapons and themselves for the ensuing battle ahead; as such Touma and Stiyl decided to sleep, here Touma discovers that Stiyl will still fight even against Kaori, just to protect Index, though he would have preferred not involving her in the situation at all.

Around the time of their preparation (before sleeping), Kamijou Touma gets into various perverted mishaps with Agnese Sanctis due to his misfortune, such as getting to see her panties, seeing her and Index naked in the shower, and her climbing into his bed in her underwear, much to his frustration.

The Agnese Forces, along with Touma, Stiyl and Index are later mobilized in the upcoming assault on the Amakusa Catholics, though with still lesser forces, as Agnese have not recalled her patrolling forces as a precaution. Agnese assigns Touma, Stiyl and Index, to investigate the park and find Orsola Aquinas, the Book of the Law, and destroy the portal, while she and her forces take on the Amakusa Catholics. Touma later asks Stiyl to prioritize in finding Orsola, as their tight schedule will not allow them to find the Book of the Law, and destroy the portal as well; Stiyl and Index agrees on this, as the Book of the Law would be useless if to them if they didn't have Orsola to decipher its contents.

Amakusa Catholic Side
Meanwhile, the Amakusa Catholics having seized Orsola Aquinas from Roman Catholic hands, have infiltrated Parallel Sweets Park and are preparing the ritual to use the portal. Though the Amakusa Catholics prepared a spell to repel passers-by, there are unaware of the upcoming assault by the Roman Catholics.

Assault on Parallel Sweets Park
The battle began at 11:30; with the sounds of battle are heard from afar, Touma, Stiyl, and Index enter Parallel Sweets Park to find Orsola Aquinas. Immediately after entering the park, they are attacked by several members of Amakusa, which forces Stiyl to escape with Index after handing the crucifix – the one that Laura Stuart gave to him for Orsola Aquinas – to Touma. Severely outnumbered, Touma is forced to withdraw and hide. His cover is blown almost immediately afterwards by a poorly placed toolbox, which attracts the attention of one of the Amakusas. Thinking quickly, Touma uses a tube of grease towards his pursuer, momentarily disabling her ability to attack him, though this gives Touma enough of an opening and easily take her down using a tackle; Touma later taks her weapon (a dress sword) away from her.

Orsola later bumps into Touma, having escaped from the Amakusa Catholics during the ensuing chaos of battle. After Touma frees her from her bounds, Orsola confirms that Touma is the one who helped her at the bus stop earlier, and asks him what he's doing in a dangerous place, to which Touma responds that he is rescuing her, and has nothing to do with the Book of the Law or the Roman Catholic Church at all (since he is allied with the Anglican Church and by their request, aid the Roman Catholic Church), which somewhat relieves Orsola, though advises Touma not to get involved with the magic side. Touma later gives the crucifix Stiyl gave to him to Orsola, who was rather enthustiastic in receiving it, and had Touma put it on her. Touma also asks why Orsola Aquinas wanted to decipher the Book of the Law in the first place, to which she replies is that she could gain power to destroy it.

Kamijou Touma and Stiyl Magnus vs. Tatemiya Saiji
The calm is interrupted by an explosion, as Touma sees Stiyl fall before Tatemiya Saiji, the current proxy-leader of the Amakusa Catholics holding a flamberge. Touma is forced to battle Tatemiya, as he intends to take back Orsola Aquinas from the Roman Catholics as well as from the Anglican Church, even though Touma is unsure himself that Saiji would be using magic or not, as Saiji not using magic would put him in a great disadvantage and would make his Imagine Breaker useless.

Touma battles Tatemiya despite his clear advantage with a weapon in hand, though Touma manages by reading his attacks, and is able to dodge. However, he is later tricked into thinking that Saiji was actually using magic; even with Index's warnings, she was too late as Touma was already hit by one of Saiji's attacks. At the same as this, Stiyl has already recovered and prepare his fire sword to attack Saiji, though Touma was in the way, he urged Stiyl to attack Saiji regardless. With this signal, Stiyl attacks Saiji and intending to pierce Touma as well, seeing this Saiji prioritize to defend himself against the explosive force of the flame sword, as such he used a spell to defend himself from the flames and underestimated Touma's strength as he already set up an anti-impact spell on himself. However, Touma uses his Imagine Breaker to cancel Stiyl's attack, surprising Saiji, and allowing Touma to punch him in the face, negating the anti-impact spell, and defeating Saiji.

In the anime version, Stiyl and Touma had to tackle Saiji after Touma punched him in the face.