Thanks for all the reviews, view, favs and follows. For a new writter seeing his story is getting this kind of response... it makes me happy and inspire me to get the updates sooner. I love to write and I love to see people are having fun with my texts.

MoRGzY1: Thank you for your review. In response to it. It's true that I mostly focused in Peter in this chapters. The thing is that we all know what was doing Touma at the Sister Arc, so it isn't completely necessary to put too much of his perspective. While Peter have to be introduced in the plot in a different way. I promise that in the next arcs, that most of them will be out of the known To Aru plot (using marvel universe characters and some villains of mine invention), I will balance the focus on both of the Misfortune Duo. Hope you enjoy this chapter.

Now, let's begin…

Disclaimer: I don't own Spiderman or To Aru Majutsu no Index, or any character from the comic and novel.

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Chapter 4 - The Secret of the Sister

"Eh, where is her?" Touma asked in loud voice in the entrance of the library.

It was afternoon. Approximately and hour ago he had an encounter with Mikoto in the park, but she seemed different from her usual self. She seemed to be sad. Not sad as if she had lost a precious friend or broke up with her boyfriend. It was a sadness similar to someone who had lost everything and was totally hopeless. Mikoto seemed to be so much into that mood that she even didn't mentioned the "difficult" experience from yesterday. Either way she walked away and Touma head to his dorm, but when he was leaving the park he found another interesting person: Mikoto Imouto (little sister). She was trying to feed a stray young cat, but the little animal was trying to avoid her touch.

"It's because the electromagnetic field that Misaka emits, Misaka explain" she had said.

It ended with Touma helping the girl. He took the cat and, along with Misaka Imouto, walked to a library to buy a book with advices about how to take care of cats. Touma had entered the library leaving the girl taking care of the cat outside. He felt confounded when, after buying the book, the girl wasn't waiting for him. She even left the cat on the floor.

"Where did she go?" Touma scratched the back of his head and picked up the cat.

He searched the street. There were a lot of students walking towards their respective dorms because of the curfew. Misaka Imouto was nowhere to be seen.

'Did she leave me with the cat? That's not very...' Touma was thinking until he focused his attention in a dark narrow alley in front of the bookstore.

Touma didn't know why he felt the need to enter into that dark place. The spiky haired crossed the street and dived in the darkness. He had the hunch that he would find Misaka Imouto if he walked that way. He found her. A few of them.

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"Now we finished our round we can go home" Kuroko said stretching her arms over her head closing her eyes.

Peter and Kuroko had spent their time patrolling their area until the afternoon. In all that time they didn't find any trouble. Summarizing it was an easy day without surprises for the Judgment.

"Tough day, wasn't it? Fuuuu!" Peter joked making a fake pose of getting rid of the sweat from his forehead.

Kuroko equally laughed at the false joke. "Yeah yeah. Do you want to return to the office before heading to your dorm?"

"I there any need?"

"No"

"In that case I will just return to my room after buying some groceries" Peter said while thinking what he should buy for dinner. "Are you also going to return to your room?"

"Yes. I will phone Uiharu in the way to report that there wasn't any kind of problem in my round."

"You don't have to buy groceries for today meal or do you have supplies" Peter asked unaware of the school of his partner.

"Hahahaha! I believe you don't know too much of Academic City."

"I just came a week ago."

"That's why you don't know anything of the Tokiwadai Middle School" Kuroko said with a smart aleck grin. "Our school can easily provide us the three meals, as a big swimming pool and one of the best esper development program. Tokiwadai is on the top of most of the schools in Academic City. Many strong espers girls are formed there. Most important, we have two of the seven Level 5 attending there" when she said this a little pervert smile reflected on her face (Peter back away a few steps), but then it turned sad.

"Shirai, are you alright?" Peter asked worried.

"Will Onee-sama returns tonight? I wish…" Kuroko muttered to herself.

"Onee-sama?" Peter asked puzzled. He had heard that nickname before. 'I remember. The little sister of that biri-biri girl called her that way.'

"Did I talked out loud? What embarrassment" Kuroko said while blushing. "Either way, there is a convenience store in the next block. Tokiwadai is on the opposite direction. So, I think I will see you tomorrow."

"Yes you will" Peter agreed without asking any question.

"I may say that you will do well in the Judgment. It was a good decision to join us."

"Do you think so?" Peter felt great thank to Kuroko's comment. "Thank you. I promise I will do my best."

"I know you will Parker-san" Kuroko nodded smiling.

"You can call me just Peter if you want."

Kuroko hesitated for a moment before answering. "If that's what you like I will. I will be going now. See you tomorrow, Peter-san."

"Until tomorrow" Peter replied with a smile.

Kuroko waved her hand and disappeared at the spot.

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Kamijou Touma was running at full speed to Academic City streets with the black cat in his arms. What he saw in the alley. The images were still tormenting his mind. He shook his head in an attempt to get them out of his mind. Misaka Imouto… there were more. There were many clones of Misaka Mikoto. Sisters, they said they were called.

'What the hell means this?'

The Sisters were being killed in "a simple experiment", which was what one of the clones said. This clone referred to herself as Misaka 10032. She was the one who wanted to help the stray cat. The one killed was another he never met before.

'10032? Is that her number? Who many Sisters exist? What are they killed for?' Many thoughts echoed in his head. 'Misaka knows about this?'

He was wondering about the last question. It was the reason why he was running to the Tokiwadai Middle School dorm. He need to talk with Misaka and clear the situation. If he remembered well, her dorm was in the same direction as his, but further away. He would have to take the bus from the next bus stop. He kept running and passed in front of a convenience store. Another teen of his age called him from there, but Touma didn't hear him.

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Peter had just exited the store after buying the groceries for his dinner before he saw Touma running at full speed. He tried to call him, but the spiky hair teen didn't hear him. In the split second he could see Touma's face, Peter saw a mixed expression of fear, rage and seriousness. Peter kept watching the other teen disappear from his sight running at full speed in the direction of their dorm.

'Maybe he is afraid of missing the curfew' Peter thought, but that didn't make any sense. The curfew didn't begin until an hour later and there were still a lot of students walking in the street.

"I heard the Anti-Skill member taking through to the radio" a student who was entering the store told his friend. "He said that somebody found a body."

'A body? Somebody found dead body?'

"Hey, excuse me, can you tell me about that?" Peter asked worried.

"About what?" the student doubted looking at Peter.

"What you just said. I heard you saying that somebody found a body" Peter had a really concerned face.

The unknown student laughed. "You don't have to worry about that. What I was saying is that I heard an Anti-Skill member talking to the radio about a murder scene in an alley a few blocks ahead. Nevertheless, apparently it was a false alarm.

"Oh, thank you. I feel now much more relief" Peter replied with a fake smile.

He was wondering about that. How exactly there was a false alarm of a dead body? How exactly there was a false alarm of a murder scene? He had seen, without joy, dead bodies and murder scenes before. Who would confound something like that?

'Who found the body?' Peter asked himself. Then he recalled when he saw Touma running at full speed with that scared and angry expression, from where the unreal murder took place.

Peter head to his dorm, where he supposed Touma had gone to. He walked the now less crowded streets of Academic City when the sun had already hide on the skyline. Peter reached his dorm and took the elevator to Touma room's floor instead of his. The teen knocked his door and waited. A few seconds passed until the teen heard somebody unlocking the door.

Suddenly his Spider Sense went crazy. The door opened and a human size projectile was shot directly to his head. Thanks to his reflexes he managed to avoid the attack ducking. Peter took cover at the right of the door frame in case there was another projectile. Nothing happened. He put out his head and look in the room. It was an empty room. There wasn't anybody that could fire a projectile or any kind of automatic turret. Peter turned around to see what happened to the first projectile. He was quite surprised. The projectile was stuck on the floor rail and it was...

"A flying nun?" Peter asked out loud.

"..." the silver haired young nun was muttering something and biting the rail like a dog would do with a bone.

"Touma... Your head taste different" the 12-13 years nun murmured with a cute voice. "Stop eating so much minerals, you don't need more iron. You taste like a key."

"A key? How do you know how a key taste like?" Peter asked out loud without thinking.

Index opened her eyes and noticed she wasn't biting Touma's head. She stopped her action and turned around to look at Peter.

"You aren't Touma" she said in a sad voice.

"No, I am not" Peter said. "My name is Peter Parker, I am Touma's classmate. Which is your name?"

"Index. By the way, do you speak English?" Index asked. Peter nodded. "I was born and raised in England and I can see you are also of a western country, so it would be easier for us to talk in English."

"Agree" Peter started to talk in English. "Hey Index, do you live with Touma?" Index nodded. "Do you know where he is right now?"

"No! He hasn't come home and I am hungry!" Index started to swing her arms over her head with anger. She was full of rage but Peter noticed a bit of sadness in her.

"I saw him running a few minutes ago. I thought that he was coming here."

"Running? Oh, he is again messing with other people problems" Index said in a tone that implied she has seen similar situation before. "He is always trying to help unknown by himself people and end up hurt."

"What do you mean? Are you saying he is dealing with something dangerous all alone?"

"He never ask for help" Index muttered in a sad tone that broke Peter's heart.

The teen took a decision. "Don't worry Index. I will find Touma and help him in wherever problem he is into." Peter hadn't felt like a hero since he left New York, but in that moment, offering his help to that worried girl he felt great. He gave his best heroic smile and said: "I will bring him back without even a scratch before you can say… hey, are you listening to me?

Index had been staring at Peter's bag, where he was carrying his groceries. Peter heard a load growl from the girl, specifically from her stomach. She did say that she was hungry. Peter moved the bag in front of her. If he move it to the left Index eyes follow. If he move it to the right, Index eyes follow. If he raised the bag higher, Index gaze looked up.

"Do you want it?" asked Peter feeling a bit uncomfortable. The nun nodded. "Take them. It's ok. I going to look for Touma. Don't worry?"

"Thank you, Peter" Index said with a tremendously cute smile, while taking Peter's dinner.

The hero teen took off leaving Index alone at door frame with the groceries bag in her hand. The little nun entered the room and closed the door with a smile.

"Let's see what we are going to eat for dinner, Sphinx" Index told her cat inspecting the contents of her treasure bag. A surprised happy face changed into a not pleasantly surprised one. "This food need to be cook. I don't know how to cook" she gave a look to Touma's room little kitchen. "How difficult could it be?"

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Chapter 4 finished. This time it didn't took me long. Of course, I wanted this to be the penultimate chapter of the first arc (the last will be the fight with Accelerator and the epilogue of the arc). But in the end I decided the next chapter to be the penultimate. The final fight of the arc and first fight of the story (I have been really eager to write a fight since the begining).

Fav, Follow, and most important: Review. Sebaspe out!