In London, the women's dorm in a magicians' base get wild, while in the underbelly of Academy City, Accelerator stumbles upon someone who has been waiting for him all this time.

Touma Kamijou just can't catch a break. He might live in Academy City, a place full of more super powered students than you can shake a stick at, but his only superpower is his supernatural lack of luck. He wants nothing more than to keep a low profile, but when a girl named Index comes into his life, it gets more complicated and dangerous than ever!

Accelerator, the most powerful psychic in Academy City, is quietly recovering from his injuries when trouble literally lands in his bedroom. A group of anti-evil zealots who call themselves “DA” are causing havoc, and it could threaten the city―not to mention the entire world! Although he hates to be bothered, a world-shaking threat may be enough to get Accelerator out of bed…especially if it involves the adorable Misaka Mikoto clone, “Last Order.”

A certain unlikely hero... Touma Kamijou has the worst luck imaginable... Sure he's a citizen of Academy City, a scientific marvel of the modern world where superhuman abilities are artificially cultivated and commonplace, but when it comes to paranormal talent, Kamijou's been classified a Level Zero-a loser, basically. Oh, he does have one trick up his sleeve (literally), but even that's more trouble than it's worth. When Kamijou encounters a delusional young girl convinced she's a nun and raving about being chased by evil sorcerers, he's eager to send her on her way and get back to failing his studies. Fate, it would seem though, has other ideas, and he suddenly finds himself caught up in a supernatural intrigue with a girl named "Index" at the center! Science and magic collide in this first volume of one of the most popular light novel series ever penned!

A certain unlikely hero...Only Komoe's class would let a regular conversation spiral out of control into a grand-scale hot pot party. It's an open question whether her students are a blessing or a curse. Meanwhile in London, the English Puritan Church's facilities should generally be a place of prayer and quiet contemplation...So who's going to take responsibility for the chaos unfolding in the sisters' dorms?! Back in Academy City, a certain railgun's mother has suddenly popped in for a visit, which is more than enough to make even a Level Five esper panic!

A short-lived respite...After bringing an end to World War III, Touma Kamijou disappears from the world. Both sides—magic and science—take time to rest and regroup. Accelerator distances himself from his troubled past and adjusts to living an ordinary life with Last Order and Misaka Worst. Meanwhile, Shiage Hamazura uses the secrets he gained in Russia as a bargaining chip and returns to Academy City to re-form Item. It seems like peace is here at last. That is, until a new group called the Freshmen bursts on the scene, forcing Accelerator and Hamazura back into contact with Academy City’s underworld...

Touma Kamijou is the unluckiest boy in Academy City. Having settled the magical side of his problems for a while, the scientific side of things starts to heat up when Touma's rival-turned-friend Mikoto meets her own clone. That's only the beginning of a chain of events that leads Touma and Mikoto to face their deadliest foe yet. Kazuma Kamachi's smash-hit light novel series continues!