Despite his misfortune, Kamijou Touma mysteriously wins a trip to Italy, and decides to take Index along with him. In Venice, they meet Orsola again who offers the two shelter at her home, but would all end up getting involved in a giant conspiracy moments after.Alongside members of the Agnese Forces, and the Amakusa Christians, Touma sets out to take down the bishop, Biagio Busoni, as well as the latest weapon of the Roman Catholic Church; a large navel ice fleet called La Regina del Mare Adriaticonote that has been set to course for Academy City.
With the considerable weakening of the Roman Catholic Church after the destruction of their knights and one of their most powerful spells. As well as the embarrassing fiascoes with the capture and execution of Orsola Aquinas, and the capture of Lidvia Lorenzetti and Oriana Thomson by the Anglican Church after the failed capture of Academy City through the use of the Croce di Pietro. Every event has been beneficial to the science side (and the Anglican Church) and has greatly increased their power.The Roman Catholic Church under the Pope finally allowed the mobilization of The Queen of the Adriatic Sea under Bishop Biagio Busoni's command, in order for the complete and utter destruction of Academy City and everything connected with it to take place. Although Biagio is concerned by the promptness of the Pope's order to mobilize the weapon, he accepts the order.As punishment for their failure, the Agnese Forces become branded as sinners, and is later forced to work mind numbing labor in the Queen's Fleet as punishment. Agnese Sanctis however, is given special privilege as the former leader of the Agnese Forces to prevent revolt among it's members, as well as a the key to changing the targeting system of the Queen of the Adriatic from Venice to that of Academy City, as she is the only one compatible found at the time even though she is a sinner. However, she is totally unaware of the history and true purpose of the Queen of the Adriatic.After the events of the Daihasei Festival, Kamijou Touma resume his activities as a competitor in the events, though he is obviously affected by misfortune all throughout the week. However, this changes after Touma wins a lottery where the prize is a 7 days and 5 nights trip for two to Northern Italy. Much to his suspicion, Touma becomes wary of the fortune blessed upon him, however he decides to take the vacation to Northern Italy anyway, with Index, despite the dubious nature of his fortune which supposedly involve the powers of Academy City and the Anglican Church.
The Queen's FleetAfter a series unfortunate events Touma and Index arrive in Chioggia as it is required for tourists and to meet up with the tour guide, though they are unable to find and the contact the person of interest. They decide to go a hotel in the meantime, however, Touma loses track of Index and becomes lost himself in a foreign land; he even attempts to communicate with a local, though very poorly. Touma is however saved by the arrival of Orsola Aquinas, who has returned to Chioggia from London to finish her move with the help of the Amakusa Christians since the move to London was rushed, she also informs Touma that Index is in her house at the moment after she found her a moment before meeting with Touma.Touma and Orsola arrives at her house and reunites with Index who is happily eating without a care in the world, much to Touma's frustration. Touma also meets the Amakusa Catholics who have come to help Orsola with her move, here, he overhears them talking about his exploits with the Agnese Forces, as well as his various run-ins with Kanzaki Kaori that he survived. Touma and Index later helps Orsola and the Amakusa with the move after having lunch (with Itsuwa of the Amakusa making advances), and later gets into perverted shenanigans with Orsola and Index, much to Touma's frustration.
After packing all her things, Touma and Index decide to part ways with Orsola, with her remaining a little bit longer in Chioggia and say her final farewells to her beloved town. Before leaving however, Index suddenly senses a magical spell directed at Orsola by a sniper, and successfully redirects the attack away from Orsola. Now aware of an enemy presence, Touma later saves Orsola from another sniper attack, however, he is later dragged into the canal waters by another assassin shortly afterwards. The assassin that emerged from the waters, tries to attack Orsola but she is saved by Index's timely use of her Spell Intercept, and Touma coming out of the waters to finish the assassin off.The assault on them is halted after Touma defeated the assassin as well as Index's Spell Intercept working on the sniper. However because of this the sniper retreats into a large ice ship that has been hiding inside the canal besides Orsola's home. The ship's rises from the canal and destroys the stone path Touma and Orsola are on which places them into the rising ship. With them unable to jump back down as the ship is still rising, Touma and Orsola decide to enter the ice ship instead, here, they take notice of how the ship is made of ice, and how it cannot be dispelled by Touma's right hand.Index is later left behind, as the ship begins to move through the canal (destroying the Ponte Vigo in the process) and into the Adriatic Sea. All the while, the ship's guards are searching for Touma and Orsola knowing that they are on the ship, they are later forced to hide within the ship to escape their pursuers. Already out at sea, Orsola and Touma try to assess the situation, here they determine that their attackers are from the Roman Catholic Church, and they were attacked because of the incident with the Book of the Law (even though that was already supposed to be settled by the Anglican Church), however, they are in disbelief that the Church would go so far to build a ship just they could attack them. However, both of them are later shaken by the realization that there are more than one ice ship and that they are all part of one massive fleet.
After trying to make contact with Index, someone from the ice ship suddenly comes into the room where Touma and Orsola were hiding. Much to their surprise it is Agnese Sanctis, and after a few attacks on Touma (and after Orsola's insistence)decides to update them on the current situation. Here, Agnese explains to them that there are one of the ships of the Queen's Fleet, a convoy of ships for the the Queen of the Adriatic Sea. She hypothesizes that the Catholics attacked them because they were enemies of the Church who were coincidentally at the right place and at the right time at one the Church's major operations, deeming them to be a threat to the operation. Agnese continues by explaining the reason why they were caught since the Queen's Fleet is primarily used for surveillance and just managed to pick them up, she however, states that the Queen's Fleet is a labor facility for sinners such as her and her former squad members.Agnese then gives them a proposal in exchange for her letting them go, she asks them to save Lucia and Angelene, as they will be punished severely for escaping the Queen's Fleet (and most likely try to save Agnese and the others). Agnese states that they know how to escape, and assures them that even if the Church detects their escape they will be too busy to concern themselves with a few escape prisoners; Agnese also adds that she'll go to the flagship to create a distraction while they rescue them. Touma asks if she wants to escape as well, though she says that she has to stay as it is her purpose to prevent a riot from occurring. Without other options open, Touma and Orsola accepts Agnese's proposal to rescue Lucia and Angelene and to escape the Queen's Fleet.
After negotiating terms with Agnese, Touma and Orsola go to the room where Lucia and Angelene are being held. Here, they encounter an ice golem guarding the room which Touma easily dispatches it with his right hand; Orsola later picks up the pieces of the destroyed golem and used it to bluff their way out of a battle with Roman Catholic peons, and later detain them. Lucia and Angelene were reluctant however on believing their former enemies, however, Orsola using her experience as an evangelist to pagan countries a convinces them.With that, Lucia and Angelene show them the method on which how they escape, however, while explaining their method, they are attacked by the power of their Forbidden colored robes. Touma however, offers to use his Imagine Breaker to negate their clothes, though he is forcefully dissuaded by Orsola. The two sister later ask when they could meet up with Agnese, however, Touma apologizes to them, stating that Agnese will not likely be coming along with them as she went to the flagship to distract the Queen's Fleet and allow them to escape. This shocks the both of them, here Lucia state that the true nature of the Queen's Fleet is to protect the Queen of the Adriatic Sea, which is the flagship and a large magic ritual center. Lucia states that they don't know the details but a key to activating it is through a spell known as the Rosary of the Appointed Time, and that Agnese would be used as the necessary sacrifice for it, which would leave her braindead.Before they could think of a plan however, they are detected by the surrounding ice ships and are attacked by them, eventually destroying the ship they are in.The entire crew of the ship that was destroyed by the other ships as well as Touma, Orsola, Lucia and Angelene, was saved by the timely arrival of the Amakusa church's submarine and are able to get away from the Queen's Fleet. Here, he is welcomed the Amakusas and Index as well. Tatemiya Saiji explains that they are on a submersible ship which was used to save them, he later states on how while Touma was unconscious his Imagine Breaker destroyed their forbidden colored robes and stripping them, as is the reason Lucia and Angelene are being shy around Touma. Of course, Index is vengeful regarding this and attacks Touma, this goes into a ruckus with which was stopped by Angelene's flipping of Lucia's robes and showing her panty to draw their attention towards her, much to Lucia's embarrassment.
Their party decides to alight at Sottomarina, to plan their next actions over dinner. Here, it is explained on how Venice was once an enemy of the Roman Catholic Church, and created the La Regina del Mare Adriatico to completely and utterly destroy Venice and it's culture. Hearing this, Angelene states that Agnese may have not known that La Regina del Mare Adriatico could be used to destroying Venice. Now with Venice's existence is in danger, the Amakusa now have no reason to back down. However, even with their expertise in naval combat, the odds are terribly stacked against them if they wish to save Agnese Sanctis and stop La Regina del Mare Adriatico, which Saiji emphasizes. However, he later reveals that they are going go through it anyway, after testing their resolve on saving Agnese Sanctis and Venice.The Amakusas, Touma, Index, Orsola, Lucia and Angelene prepare their weapons for the battle coming ahead. They depart on one of the Amakusa's ships that were created from paper using magic. Lucia prepares her weapon of choice, the St. Catherine's Wheel, while Angelene meticulously tries to prepare her weapon, the Coin Bags of St. Matthew for the battle up ahead. Index gives Agnese's Lotus Wand to Orsola for use, as Index herself cannot use magic.The strategy was for Saiji using the boats realized from paper as a decoy to attack the ice ships and weaken the defenses, whilst their submarine would be meant to confuse the enemy, believing their forces to be still be in the submarine and take them out immediately. Finally, after the boats on the frontlines has weakened the defenses, the boat that were left in the back (which carried their forces) would board the ship and attack.
Ship 43, under the helm of Sister Agata who receives orders directly from Biagio Busoni himself, detects a several ships approaching the ship. Under the orders of Biagio, Agata is instructed to destroy the ships, which the firepower ice ships of the Queen's Fleet more than capable of performing. However, Agata soon notices the apparent lack of counterattack or retreat from the Amakusa's ships, and simply kept moving forwards towards the ships. Sensing danger, Agata orders the forces to go on defensive mode.Agata's hunch was correct, the remaining Amakusa ships unscathed by the cannon fire, plow into the ice ships and explode violently upon contact. Under the confusion, Agata is forced to attack the Amakusa's submarine after being detected, believing it to be their main base of attack, she orders an attack on the submersible vehicle which quickly sinks it. However, it is later discovered that one of the ice ships have been boarded by the Amakusa themselves, and have utilized the other ships and the submarine as a decoy for them to pass through the defenses.Immediately after, Touma is ordered by Saiji to focus on destroying the core of the Queen's Fleet, La Regina del Mare Adritico. With time running out as the other ice ships begin their firing at the boarded ship, Orsola and Index tag along with Touma where they move from ship to ship. While moving towards the flagship, former members of the Agnese Forces who work on the ship surround them even though what would happen to Agnese. Lucia and Angelene later arrive to break up the massive disadvantage, though they are perplexed on why they are not helping in saving Agnese they still fight their former comrades. At the same time as this, cannon fire from the nearby iceships begin which injures Angelene after trying to prevent them furthering the damage on the ship they were on and to save their former comrades. Not long after, the Amakusa arrive on the ship Touma and the other's were on to back them up. Saiji later gives her a paper bundle that would transform into ships for later use. Here, Lucia checks to see the condition of Angelene, and promises to her (after prompting from Touma) to protect everyone, even their former comrades. With this, Lucia and the Amakusa continue to battle the remnants of the Agnese Forces, while Touma, Index and Orsola continue to traverse towards the flagship. The nuns are later rescued by the Amakusa after defeating them in battle.Touma, Index and Orsola arrive at the flagship, here they discover that the Queen of the Adriatic Sea has no human guards, and is supplying the regenerative magic to the fleet. Touma discovers that can use his Imagine Breaker to dispel blocks of the ship. They are then however attacked by several ice golems; outnumbered, Touma, Index and Orsola run inside the ship. While being chased, Touma tells Index and Orsola to go on without him as the ice golems were trying to attack him as he was the most dangerous opponent to them, due to the Imagine Breaker. With this, the golems pursue Touma alone who destroys parts of the ship with his Imagine Breaker to open new routes for him to escape. After a couple of tussles with the ice golems, Index and Orsola calls him, asking him about the Rosary of the Appointed Time. Index states that the Rosary of the Appointed Time is not in any of the grimoires inside her head associated with the La Regina del Mare Adriatico, since the weapon can now be used on Venice without the aforementioned additional spell, and suggests that is a plan known only to the inner echelons of the Roman Catholic Church.
His conversation with Index is cut after Touma is attacked by Biagio Busoni himself, who mocks Touma's right arm. They do battle, with Touma intenting for Biagio to tell him where Agnese's wheareabouts. Biagio uses several crosses to attack Touma, who is overwhelmed by it as he is unable to cancel it all and fight Biagio in a confined space. This forces Touma to retreat during one of of Biagio's attacks. However, Touma is later cornered by Biagio and is trapped. Here, Touma discovers that Biagio is not actually planning to destroy Venice using the La Regina del Mare Adriatico, though before knowing the whole truth, Biagio pins him to the ground using his magic and crushes him with several cross attacks. Believing Touma to have died, Biagio leaves.Orsola Aquinas goes to the room where Agnese Sanctis is held alone, as Index willingly acted as a decoy for the ice golems using the ice golems. Upon her arrival, Agnese is visibly surprised by her appearance as she expected that she and the others have escaped the Queen's Fleet already. Orsola says to Agnese that once they knew nature of her sacrifice, all of them, especially Lucia and Angelene wanted to save her regardless of the danger.Biagio Busoni however appears before them and states that even Agnese escaped, the spell would still be activated as the Church only needs to find a person compatible within their members, though Biagio states that is too troublesome and comments that he dislikes troublesome things. Orsola demands why Biagio needs to use La Regina del Mare Adriatico to attack Venice, to which Biagio simply responded that Venice is not his target and hinted that he us using the Rosary of the Appointed Time to change the target of the weapon since it can only target Venice to that of the enemy city, Academy City. Hearing this, Orsola tries to attack Biagio using the Lotus Wand, but is easily repelled with his attacks.
With Orsola down, Biagio urges Agnese to synchronize with the Rosary of the Appointed and the Queen of the Adriatic Sea. However, she resists his orders after Orsola Aquinas still tries not to yield to Biagio, here, Agnese states that she will fight to protect her forces, and stop his order. Agnese tries to fight back, however, she is swiftly repelled by Biagio's powers. Agnese, however, notices the true nature of the spell that was activated on both her and Orsola. With this Kamijou Touma arrives after surviving his attacks, just in time to dispel Biagio's hold on Agnese and Orsola, and then beat Biagio.Thinking Biagio is unconscious, Touma thanks Agnese for protecting Orsola. Touma then asks how to stop the La Regina del Mare Adriatico, to which Agnese states that the room they are in cannot be replaced, as such destroying the place they were in would destroy La Regina del Mare Adriatico. However, before finishing her sentence Agnese suddenly collapses to the floor and curls up in pain, seeing this, they discover that Biagio Busoni has come to and has used the Rosary of the Appointed Time to redirect the power of the La Regina del Mare Adriatico to self-destruction. With the weapon slowly activating, Touma orders Orsola to get herself, Agnese, the Amakusa as well as the Roman Catholics to escape, while he stops Biagio. Orsola reluctantly agrees, and promises to meet up with Touma again.
After leaving, Biagio states on how the plan to use the weapon was too soon, and insults the Pope's decision for allowing it, and consoles himself regarding his failure. Touma calls him out regarding this, to which Biagio does not deny, and states that this would be his final act for his glory, and the will of the Roman Catholic Church. Angered by the total opposite of Biagio's thinking to his, Touma attacks, to which Biagio gladly receives his hostility seeing Touma's unyielding will as the threat to the Church. Biagio bombards Touma with several cross attacks, to which Touma easily manages to dodge, however, after getting nearly close to him, Biagio propels Touma several meters away using another cross spell. Biagio asks why he'd go to such lengths for a woman who will not be accepted by anyone, however, Touma states that he doesn't care about that, and begins towards Biagio again. Seeing this, Biagio uses one of his crosses that expands to attack Touma again, however, anticipating this move, Touma uses his left hand just as the cross was expanding to make Biagio lose his balance, with his right hand free, he punches the crosses on Biagio's chest, stopping the self-destruction and defeating him.Touma states that regardless of how many followers the church has, if he or the Church continue to pursue Agnese, then he will deal all of them no matter times it takes. With the core cross destroyed, the La Regina del Mare Adriatico slowly splits and crumbles apart into the Adriatic Sea.
AftermathTouma is later taken into an Italian hospital, with Index with him. Touma later gets a call from the Heaven Canceler who orders Touma to take the Academy City supersonic jet that is awaiting for him in the local airport. The frog faced doctor also tells him about a certain girl that told him to pass a message to Touma about the Penalty game she won from the Daihasei Festival, with this Touma immediately recognize the girl as Misaka Mikoto. Hearing this, Touma demands to stay in Italy instead of going back to Academy City. With all that occurred during the arc, not even a single full day was spent in Italy.
Back in London during midnight in the Anglican Church Women's Dormitory, Kanzaki Kaori receives a report regarding the events with Kamijou Touma and the Amakusa from Tsuchimikado Motoharu, where it is indicated that both Academy City and the Anglican Church may have had a hand in the events. After an argument with Motoharu, Orsola arrives into the dormitory bringing with her a very shy Agnese Sanctis.Meanwhile, in the St. Peter's Basillica in the Vatican, the Pope and a mysterious person known only as Vento of the Front of the God's Right Seat, discuss the failure of Biagio Busoni's use of the La Regina del Mare Adriatico, and on how he has mysteriously disappeared after the incident (though it is shown later that he was capture by the Anglican Church and was sent to the Tower of London). During the conversation, Vento of the Front threatens the Pope with her words, indicating that she has power beyond that of the Pope himself. Vento of the Front later hands out a piece of document to the Pope for him to sign before leaving; the document indicates to investige Kamijou Touma of Academy City, if he is an enemy of God then he will be killed. With the order to be carried out in five days.With the losses incurred by the Roman Catholic Church, such as the lost of the Gregorian Chant, their Knights, the Agnese Forces, the Croce di Pietro, the capture of Lidvia Lorenzetti and Biagio Busoni by the Anglican Church and finally the lost of the La Regina del Mare Adritico, the God's Right Seat has finally started to move in an effort to subdue one common factor in all these events, Kamijou Touma. As with the Touma's hometown being Academy City of the science side, Vento of the Front and the Roman Catholic Church would finally try to directly attack it, and spark the war that has been building up for a very long time.