A/N: Hello there! This is my first fic outside of the L&S category in quite a while, but I couldn't let this plotbunny go to waste! Sorry if the characterisations are a bit off, as I'm rather new to the series, but I'm always open to suggestions.

As usual, To Aru Majutsu/Kogaku no Index/Railgun is the property of Kazuma Kamachi, ASCII Media Works, JC Staff, and probably a few others that I don't recall. Thank you, guys and girls, for your excellent work on the series.

A Certain Vanishing Act
Chapter 1: Robbery

"Hurry up! We don't have all day."

The store owner flinched as the butt of the rifle impacted his back. Quickly, he shoved the remainder of his money into the outstretched bag before him.

Holding that bag was a grisly man wearing a jet-black jacket over his blue-grey shirt. His hair, wild and grey, looked like it had not been combed in at least a month, if not longer, and while he had clearly shaved in the past week, bits of stubble had already started poking out.

"And your electronics too." He turned to a group of customers huddled in the corner of the shop. "You too! All cell phones, in the bag, now!"

The customers all complied, guided by the guns of two other crooks, looks of fear evident on their face. The criminals could see they were hoping Anti-Skill would arrive soon. They weren't to have such luck, not if they could help it.

"Alright, let's hurry." They turned to face the locked-down entrance, barricaded by steel sheets. "What a pain they always make it." He placed his finger along a groove in the metal and pushed through.

To the great surprise of the trapped crowd, the finger sliced the metal easily, leaving the bottom half to collapse by itself.

"Now, let's move out. "

They headed towards a nearby alleyway, sure that no-one was following them. After all, it was late in the afternoon, and everyone was either at home or in the parks, enjoying the last rays of sunlight.

"We did it!" shouted one of the henchmen, and they shared high-fives all around. They doubted anyone had pulled off a heist this big within the confines of Academy City, and if it wasn't for one of them being a Level 1 electromaster – not very powerful, sure, but just enough to disable the Anti-Skill alarm implanted in the building – they doubted they would have made it thus far.

"Not quite." A voice pierced the groups' cheers – a stern, feminine voice. The group looked up to see a silhouette of a rather short person, their hair tied up into at least three loops. A pushover by any standards.

"Who are you, and what right do you have to tell us what we did or didn't do?"

The person didn't answer the question. Instead, she stuck out her finger and shook it in a tut-tutting manner, as if scolding a child.

"You know, it's not nice to steal from unsuspecting storeowners. Not nice at all."

The silhouette stepped into a ray of light, and they saw who it was.

"A schoolgirl? Do us a favour and run to mother, us grownups are busy."

The girl smirked. "Do not underestimate me." She placed her hand on her shoulder band, green with a white shield emblazed upon it, to make sure the crooks noticed it. "I'm with Judgement."

"That's a Tokiwadaian," one of the men laughed, pointing to the beige vest she was wearing. "Hey, don't you have a tea party to attend or something?"

"I'm warning you, drop what you have stolen and surrender yourself. I'm placing you under arrest on suspicion of robbery, armed assu-"

"Sorry, my bad," the leader said with a sarcastic sneer, dropping the bag of stuff in the process. He then gestured with his head for the two crooks to attack.

"Ah, I was so hoping for you guys to surrender quietly." She dodged both of their punches easily. "And now I'm missing Onee-sama's shower. What a shame."

One of the grunts had evidently had enough; grabbing his gun, he aimed the handle for her head, but was surprised when all it met thin air.

He looked down at his hand, and back to the gun. The girl was gone.

"I told you not to underestimate me," the voice of the girl floated across the alleyway, echoing off the walls. "I guess you'll just have to learn the hard way."

All of a sudden, one of the thugs slammed against the wall; the next instant, he was pinned there by his clothes with small spines. The other thug looked around wildly, confused as all heck as to what was going on.

"Is that… a-a g-ghost?" The pinned guy was becoming more and more panicked by the second.

"G-ghosts don't exist!" exclaimed the other, even as his voice wavered – evidently he was having second thoughts.

The leader touched his hand to his head in shame. How he'd made it thus far with these two, he didn't know.

"You fools, she's an esper!" he shouted to them.

"Yes, that's true," the voice replied. "Want a demonstration of my ability?"

The remaining thug glanced around uneasily. He wouldn't be caught off guard.

But as quick as the blink of an eye, he heard a pop, and felt a finger touch his back. He made to turn around, intending to give the person a piece of his mind, only to find his face smashing against the wall.

How did he get there?

The very next instant, scores of spines were pinning his clothes to the ashen bricks, just as the other had been.

"Now, I grow weary of this. Shall you surrender, or meet the same fate as your friends?"

The man in the black jacket grimaced. He had had enough of these children's games.

"Look, little girl, if you want to play, why not come out and get me then?"

Grabbing a nearby metal post, he crushed the bottom until it came free. This would be perfect for knocking out that little brat.

"Oh, fine. But only because it amuses me."

He listened carefully to the silence around him. She was not going to get him. He was ready.

A popping noise behind him. She was his now.

He threw the full weight behind swinging the signpost behind him, catching the girl in the chest with the plastic sign. He could clearly see a look of surprise on her face before she fell to the ground about a metre away.

"I have heard of your ability, little girl," the man said snidely, slowly walking towards the girl as she tried to get up, her shallow breathing echoing across the alley. "Teleporter, they call it. But, you see, it is no match for me!"

At this he thrust his bludgeon towards the girl.

The next second, he felt a shoe slam against his skull.

"Since you keep underestimating me," the girl said, "you would do well to remember my name. I am Kuruko Shirai, and you have been defeated."

The man felt his body sprawl across the ground, and then his clothes become taut, most likely from the girl's spikes pinning him to the ground. He had lost.

And with the world spinning around him, his sight faded to black and he saw no more.

"You shouldn't have worried."

Kuruko smiled at her friend, a young girl with short, black hair and the most peculiar hairband – one adorned with many flowers – as she lept up from the chair she had been sitting at. While Kuruko wore a beige vest over her plain white shirt, tucked neatly into her short grey skirt, the other girl didn't wear a vest at all, and her skirt was blue and much longer than Kuruko's.

"But I did!" she said. "You mustn't take so many risks!"

"She's right," said a much older teenager, one with long black hair, who was sitting at one of the many computer consoles that littered the headquarters of the 177th Branch of Judgement. "Remember, Judgement isn't always about getting the bad guy – sometimes you should wait for Anti-Skill to arrive. Personal safety is your number one priority, once the safety of the public has been assured."

"But I'm fine," Kuruko tutted, despite every part of her ribcage aching with agony.

"Oh, you're so strong!" the flowered girl said, and with that she gave Kuruko a big hug.

"Stubborn, more like it," muttered the teenager as Kuruko struggled not to scream.

"Er… would you mind… letting… it's not… the pain but…"

"Oh, sorry!" She let go quickly.

"Look, I have to think of your personal safety," the older girl said. "Because of that, I'm suspending you from Judgement pending your full recovery."

"Wha… what?" Kuruko's jaw dropped slightly. "But Senpai, I can't just… I'm fine!"

"The examiners have requested you rest until you're fully healed. And anyway, with that area tender for the next few days, it's going to be a liability."

"Kinori-san, here's the papers you requested," muttered a man who had just walked in.

"Ah, yes, thank you." Mii Kinori nodded, and the man left.

"Anyway, this is my final decision. I just can't have you parading around with a broken rib, and you need the time to heal." Mii smiled. "Think of it as an opportunity to get some much needed rest and relaxation. A vacation, of sorts. You've been working too hard lately, you need a break."

"But Senpai…"

"My mind is made up. Please don't push the issue."

Kuruko folded her arms in a pout.

"So, Uiharu-san, how are the reports coming?"

Kazari Uiharu, the flower-adorned girl, faltered – in the drama surrounding Kuruko's injury, she had forgotten about them.

"Right on it, Kinori-sama!" She rushed to a computer and began to type.

"He had the most unusual ability." Kuruko raised her eyes in remembrance. "He could just… tear though stuff. Super-strength, perhaps?"

"Metal-Rule," read Uiharu as her hands blazed across the keyboard. "It allows him to control metal products by touching them."

"Only Level 2?" Mii stared across Uiharu's shoulder. "That'd explain his limited control of it – he didn't try anything more advanced than cutting or crushing it."

"Yes, and wasn't one of them an electromaster? He didn't even try to use his ability." Kuruko tapped her head. "Shoddy work all round, I'm afraid."

"'Shoddy'?" Mii frowned. "You should probably consider yourself lucky that was it."

"Well, it is as it is." Kuruko turned towards the door. "You wouldn't mind if I headed for home, ne?"

"Not at all. But remember to keep off your stomach!"

"I will, senpai!" Kuruko called as she ran out the door.

Mii sighed. She didn't know what she was going to do with that girl.

The skies above Academy City were lit with a strong orange-reddish glow, hinted with gold where the rays of the sun licked the clouds. The golden majestic orb itself had seated itself on the horizon, threatening to slip off completely into the dark depths of the world beyond. Kuruko sighed and smiled as she walked – even in the depths of the city, where skyscrapers and trees interrupted the view before her, it was still a beautiful sight.

Presently, she became aware of someone shouting. She sighed – people were always shouting at one another. But then she realised the noise was getting louder.

"Sumimasen! Sumimasen!"

She turned to see a woman rushing towards her. She had to be in her mid-twenties, black hair to her shoulder, and was wearing a white shirt with a long black dress. Kuruko was certainly puzzled; she had never met anyone fitting that description before.

And wasn't that kind of clothing a little too formal for someone who didn't have to go to school?

When she caught up, Kuruko waited a moment for her to catch her breath.

"Excuse me, but do I know you?"

The woman gave her a look of puzzlement. "Aren't you with Judgement?"

"Judg…?"

Kuruko glanced at her arm – she had forgotten to take off her armband.

'Gah!" she exclaimed, grasping the armband suddenly. "Well, yes, but I was going off du-"

"You've got to help me look for my boyfriend," she continued, hardly pausing between words. "We were shopping for groceries, and then we went outside, and I looked away for a second, and then…. and then…"

She fell to her knees, bursting into tears.

"Er… don't cry… it wasn't your fault," she said, trying to console the poor woman.

"But… he's probably been mugged… or worse… and if I hadn't…"

Kuruko considered her options. She was going off duty, and Konori-san had told her to be careful, not to mention it would mean far less time with her beloved Onee-sama… but on the other hand, it would probably just end up to be a case of just missing each other, and they'll find him in the park or something. And it was her duty as a member of Judgement to help the public.

She sighed. She wasn't used to consoling people, not at all.

"Uh… don't worry, I'm sure he's fine… he's probably waiting for you somewhere… er… why don't you show me where you last saw him…"

She offered her hand. The woman, at this small gesture, stopped, sniffled a little, and accepted it.

Kuruko reached for her cellphone. The search was not going well. She'd checked the grocers', the alleyways, the park nearby… she'd even teleported to the rooftops and searched each nearby one. To make matters worse, the woman's home phone had picked up on the answering machine, and no-one had rung back since.

Meanwhile, while the woman hadn't resumed crying, her constant sniffles were beginning to get on Kuruko's nerves. She knew she shouldn't be annoyed – the woman had every right to be upset, after all – but this didn't stop her from twitching uncomfortably every time she heard a sniff.

She quickly glanced at the sky – now a deep purple, with small lights beginning to litter themselves across it. It was getting late – very late.

She selected a contact from her list and hit the Dial button.

"Moshi moshi!" a voice said on the other end.

"Hey, Senpai, I have a small problem."

"Why, are you OK? You haven't been injured futh-"

"No, nothing like that." She waved her left hand, as if it would wave away her concerns. "No, I've been helping a civilian trying to find her boyfriend. No luck, I'm afraid."

The voice of Mii sighed at the other end. "You know I said… well, never mind, it can't be helped. We'll send someone over to pick her up, and then interview her for more details. Just hold on a bit."

"Can do, Senpai." She checked the signpost above her, then flinched slightly.

That was odd. Why had she done that?

"Er… we're at the corner of Roman Road and Hazel Street."

"OK, got it. See you there."

"Ja ne."

As the call ended, a slight breeze picked up. Kuruko shivered. She hoped they arrived soon, so she could go home – her warm, cosy home – and forget about this whole incident.

With weary arms, Kuruko fumbled with the door handle and pushed it open, then slumped in, shuffled her way across the room, and collapsed on her bed. She'd had enough of today, and couldn't wait until it had ended.

Sitting at a desk across the room was another girl, one with short brown hair. She wore the same uniform as Kuruko – that of Tokiwadai High School.

At this moment, Mikoto Misaka had been contemplating how she should finish her essay on Personal Reality, her pencil touching her mouth every now and again as she thought. But when Kuruko had entered in a fashion so unlike her normal self, she couldn't help but stop and stare.

"Er, Kuruko-san… is anything the matter?"

"Nothing," came a muffled groan from Kuruko's bed.

"Also," continued Mikoto, checking her cellphone, "it's well past curfew. Where have you been?"

But Kuruko didn't reply.

Mikoto sighed. "Sometimes, I really worry about y-"

"Kuruko Shirai, it is well past curfew!"

The door swayed open dramatically, revealing a tall woman with dark brown hair, tied in a knot, dressed from head to toe in black clothing. This woman marched across the room and, grabbing Kukuro by the ear. dragged her to her feet.

"Ow ow ow ow ow ow!"

"Well, you do know the rules," said the dorm supervisor, reluctantly letting go of her ear. "You are meant to be…"

"B-b-but I have a reason!" Kuruko stammered.

"A reason, or an excuse?"

"I was helping someone track down a missing person!" she protested. "We are meant to help the public, as part of Judgement! Ask Kinori-senpai, she'll back me up!"

The supervisor pursed her lips. "Fine, I shall take that into consideration when deciding your punishment tomorrow. Now, prepare yourself."

She placed her hands to the sides of Kuruko's head.

"Bu-bu… I have a serious injury!"

The supervisor paused, then, removing her hands from Kuruko's head (much to her great relief), pulled out her cellphone and started tapping the touch screen.

"Hmm, it seems you are correct." She put the phone away. "But don't think I'll forget this."

And with that, she walked out, slamming the door shut in her wake.

"Phew." Kuruko wiped her brow, then slumped back onto her bed.

"A… serious injury?" Mikoto asked. Kuruko had probably tried to bite off more than she could chew… again.

But this was the first time she'd copped an injury that she would describe as serious – in fact, not since the Level Upper incident had she gotten hurt in all but the most minor sense.

"Oh, it's nothing," muttered Kuruko dismissively. "Just some jerks who didn't know when to quit."

"Sounds ironic, considering what happened," replied Mikoto.

"I caught the bad guys. That's what's important.

Mikoto frowned. "But you've got to take care of yourself as w-"

Kuruko waved her hand as if to dismiss this comment. "Senpai already gave me the lecture. 'Your own safety is second only to public safety.' I got it." She mimed her superior's head talking with the other hand as she said this.

"Well, you should listen to her."

Kuruko rolled onto her side, head facing away from Mikoto. "Whatever. Right now, I just want to sleep."

Mikoto let the subject drop. It was no use arguing with Kuruko when her mind was set, especially when she was as tired as she was.

"Good-night, then." She walked over to the door and switched the light off, leaving her table-side lamp as the only souce of light in the room.

"Night, Onee-sama," replied Kuruko, closing her eyes.

Mikoto looked at the outline the lamp cast on her roommate, her body rising and and falling with each breath. To be sure, Kuruko was a unique individual, even if she often irritated her to no end.

But one of these days, Mikoto feared that she'd try and take on someone much stronger or smarter than herself. Much of the mooks they'd faced in the past were brash and undisciplined. They had been easy to outwit or overpower.

She sighed. She probably shouldn't worry about such things.

"Sleep tight, Kuruko," murmered Mikoto, taking one last look at her sleeping friend before turning back to her essay. "Sleep tight."