Toaru Majutsu no Index Light Novel Volume 15

Publisher's Summary
The security forces in Academy City have all been deployed in Avignon as part of Academy City's invasion plan. The city becomes a lawless area of sorts, and organizations that belong to the darkness initiate their secret operations.

— One who moves only for himself. — One who basks in the darkness and enjoys heartless slaughter. — One who lives as a disappointment to others. — One who fights on for the sake of someone precious. — One who challenges others to reach the top. — One who eliminates a certain rebel. — One who holds back a rampaging streak of violence.

Science is now lead into a certain path, and to survive...

When [GROUP]'s Level 5 Accelerator encounters the mysterious organization [SCHOOL], the story shall begin!

Prologue: The Finest Lead Bullet for You, My Dear — Management.
Tsuchimikado Motoharu meets up with a man only known as "Management", one whose expertise is logistics, especially in shady operations like robberies, money laundering and others. However, Tsuchimikado is not there to settle some underground deal with Management; he is there to eliminate Management. He manages to finish his job quickly, and he contacts the other people involved.

GROUP is on the move.

Chapter 1: An Unmistakable Gun, Unheard by All — Compass.
October 9 is supposed to be Academy City's independence day. Last Order heads back home after being discharged, and Accelerator reunites with the Frog-Faced Doctor with a gun on his hand. The Level 5 demands for plans of the device maintaining his ability, and as quick as he appears, Accelerator vanishes when he already has the schemes on his hand via a USB storage device.

Meanwhile, Tsuchimikado asks Unabara Mitsuki to extract information from Management's hideout; the magician-esper hybrid needs to learn who Management's last client was, and stop it before it could harm others. However, most of the evidence was destroyed by several armed men in a sudden attack.

GROUP meets at the scene of the siege, except for Unabara. In the middle of their attempt to look for evidence that survived that attack, Accelerator unexpectedly digs up something vital to their mission. They soon discover a corpse of a man who had his skin peeled off, and they realize that Unabara is on a covert mission himself.

In one stopover in the middle of the trip, Last Order decides to alight, and the nervous driver asks help from Uiharu Kazari, who easily catches Last Order.

GROUP soon discovers that the grunts who are supposed to take Management have been knocked out and Management is missing, oblivious that a boy with a strange head accessory has just executed Management. Tsuchimikado soon decides to decode whatever data they can trace from the money they picked up, and it reveals its last user: Sunazara Chimitsu, who used the money to purchase an MSR-100 magnetic sniper rifle. Although they haven't determined whom he was working with, they manage to trace simple plans on Sunazara's sniping plan.

That night, they attend a cultural festival event and Tsuchimikado and Accelerator waits as the target, Director Oyafune Monaka, recites a speech in front of a crowd. They determined that the director is Sunazara's target, and now they have to guess on which spot the sniper will position itself for the kill. For a moment, they are forced to stand down when Uiharu Kazari, Last Order and someone dressed in a maid's outfit appear in the crowd, and there, Sunazara strikes.

However, Director Oyafune survives. And Accelerator gets a visual on the sniper.

Later, Tsuchimikado reports that Oyafune survived, but they failed in retrieving the sniper. Meanwhile, Awaki manages to extract the information they struggled to get earlier: Sunazara works for SCHOOL, another of Academy City's underground organizations.

Between the Lines
A man called "Professor" talks to a woman in a red seifuku. They discuss about things "a magician cannot understand", the Professor's "pet" reports about the movement of GROUP and SCHOOL and the possibility of the movement of other underground organizations as a result. Meanwhile, all they decided to do is wait.

Chapter 2: The People Who Have Slowly Begun To Move — Hikoboshi_II.
Even underground organizations go hungry as well. At lunch time, GROUP's Accelerator, Tsuchimikado Motoharu and Musujime Awaki dig in on their respective lunches, while another underground organization, ITEM, is served by none other than the Level 0 Hamazura Shiage. Soon, they discuss on the assassination attempt on Director Oyafune Monaka and the reason behind's SCHOOL's act.

Meanwhile, Unabara finds himself in a challenging situation when he discovers that he borrowed the identity of BLOCK's tactician Yamate. Right now, he is trying to keep himself out of suspicion, and it involves taking out one of their members, a girl named Tetsumou, whose ability is to peek into a person's identity.

Soon, GROUP receives news of an attempt to hijack the Virus Isolation Center in District 5. They soon head off for District 13, where one of the four terminals connecting Academy City to the world via the Internet is still working. On their way, however, they discover that the weather satellite Hikoboshi II was being hacked, and Accelerator decides to go to District 23 to investigate.

A similar call was received by ITEM, but ITEM's leader Mugino Shizuri decides to focus of SCHOOL for the meantime; with Shiage hijacking a vehicle for ITEM, they drive off to District 18. When they reach Kirigaoka Girls' Academy's Particle Engineering Laboratory, they face a skirmish against SCHOOL's Level 5, the Rank 2 Kakine Teitoku, and the Rank 4 Mugino is forced to flee with fellow member Takitsubo Rikou. Meanwhile, another member of SCHOOL begins to pursue Shiage, but he narrowly escapes.

Accelerator is on his way to District 23, and after learning how Hikoboshi II's orbital laser works from GROUP's informant, he receives news from Unabara that the hacking of Hikoboshi II is BLOCK's doing, with the plans of eliminating GROUP. Upon arriving, however, he is attacked by one of MEMBER's operatives, who can teleport to the back of anyone at will — Kill Point. In spite of his ambush ability, he was easily disposed of by Accelerator.

Soon, Accelerator destroys the link between Academy City and the Hikoboshi II satellite. Without the surveillance capabilities of Hikoboshi II, Academy City can now be accessed with little intervention. BLOCK has this prepared already, with 5,000 mercenaries ready awaiting the go-signal.

Between the Lines
The Professor contacts SCHOOL's Teitoku Kakine and introduces himself and his destructive nanodevice called "Mimosa". Although the Professor is supposed to kill off Kakine using the Mimosa, Kakine manages to escape unscathed.

Chapter 3: In the Land of Sealed Powers — Reformatory.

 * Chapter 4: The Paper-Thin Difference Between Self-Derision and Pride — Enemy_Level5.
 * Chapter 5: Defeat the Person with the Strongest Black Wings — Dark_Matter.
 * Epilogue: The Victory Prize for Those Who Survived — Nano_Size_Data.

Summary
Chaos breaks out in Academy City when the city's underground organizations battle and race against time to obtain an important artifact before the others. In this volume it's completely Accelerator centered. We get to see various underground organizations such as GROUP, ITEM, SCHOOL, MEMBER, BLOCK. Volume 15 is also where we learn about Kakine Teitoku, the 2nd ranked level 5 who harbours extreme resentment towards Accelerator as he wanted to be used for the level 6 shift project. Many groups battle it out and many crumble. There are a lot of deaths in this volume and extreme foreshadowing such as Kakine figuring out what "awakening" is but before he can explain Accelerator smashes him into the ground. Mugino Shizure also kills Frenda due to her being a traitor and trying to defect to SCHOOL. Hamazura takes out Mugino. GROUP was the only team left intact by the end of this volume.