"Oi, you! Get the hell out of here!", Sergeant Gregson barked.

The words where obviously directed at Sherlock, but the boy looked oblivious, too busy crouched under the washbasin, feeling the floor with both hands. John had no idea of what he was doing, but at the insistence of Gregson's shouts, the boy raised his face and looked expectantly at John. Okay.

John took Gregson's sleeve. The Yarder turned to look at him, annoyed at first, and incredulous when he finally met John's face and realised who he was.

"You again? What the fuck are the two of you doing in another crime scene, mister…?"

"Watson. Look, Sergeant, this boy is really clever and intuitive; you wouldn't believe the amount of details he can observe in a moment…"

"Get the boy out of here, Mister Watson. And please, disappear yourself, got it? You cannot be here, my colleagues are trying to take pics."

"We will go off right now, of course; nothing furthest of our minds that bothering you and your colleagues. Scotland Yard has all our respect". John could see Sherlock with the corner of his eye; his student gestured him to go on. "In fact, I wanted to talk you about this boy, because he really admires your work and would like to be a Scotland Yard officer one day…"

"That's all really fine, Mister Watson, but please now…"

"I know, I know! I just wanted to thank you for your work here at the school; you make the girls feel somewhat safer. And… are you sure you don't want to hear Sherlock's impressions on the attacker? He is quite impressive, you know…"

"Mister Watson!" Gregson shouted, a thick vein in his forehead trembling. "Off you go, now!"

"But of course! Just… one last question. Can I know the name of the victim? Just to know if it was again one of my pupils…"

The cop sighed and rubbed his forehead, soothing his poor vein.

"Her name is Saskia Jankowska. She's been taken to Queen Elizabeth Hospital, if you want to inquire."

"Thank you very much, Sergeant!"

John grabbed Sherlock's arm and pulled him out of the toilets. The officers had already put yellow tape, with the "no crossing- Police investigation" letters, out the door, and the group of onlookers was even larger than before. The bell chimed, the Head Teacher approached the crime scene, and suddenly all the people disappeared, heading for their classrooms. Sherlock and John slipped into the next boys' toilet.

"Sorry I couldn't buy you more time", John said at once. "What do you have?"

"I don't know the girl, but she is not in Sixth Form, so she is younger than Claire. We will go for same height, perhaps a couple inches less…"

A boy came out of one of the stalls, looking at them with curiosity.

"You are late, please do hurry!" John urged, and the boy jumped in surprise and ran out the door.

Sherlock kept pacing as if anyone had interrupted them.

"I could do with some help from your part, do you mind, John?"

John shrugged.

"Of course; what do you need?"

"As you are more or less the same height of the victim… and I'm more or less the same height of the attacker…"

"Oh, I know", John sighed. "OK. Where am I, what posture?"

"Come here… I could see the girl when they were taking her out in a stretcher, just a glimpse, but with the position of her injury re-enacting the attack is child's play… You, John, come from the stall and go to that washbasin to wash your hands…" He stopped for a moment while John came nearer the washbasin Sherlock was pointing to. He opened the tap and turned to look at Sherlock, expectant. "The attacker came from behind. This time he was wearing some kind of mask or balaklava, because the victim had a mirror in front of her and could see him coming. He took the girl by her neck". He approached John from behind and anchored his left arm around the teacher's neck, like a python. "With his other hand, the dominant one, he forced the girl down". He acted that part too, and John gasped when his forehead touched the cold tiles in front of him. "The victim struggled to get free, and the man hit her head against the mirror, which cracked. I'm not sure if the victim lost consciousness or not with this."

Sherlock pushed John's head down, against the washbasin, his torso glued to his teacher's back. John was suddenly very aware of the warmth and muscles enveloping him, and he refused to acknowledge if there was a hardness pushing against his bum or not. Instead, he focused in keeping his own breath even and in the details of the rape.

"I… I don't think so", he managed to mumble. He was keeping his balance with one hand on the cold china, and then used his free hand to pull at Sherlock's wrist. "You are cutting my breath…"

"Sorry". The grip loosened a little. "Alright, the girl was conscious. But in this posture, she couldn't move much. The attacker used his dominant hand to push her trousers and underwear down… That part is clear as day, so there's no need to re-enact it…"

With that, he let go of John completely. The teacher stood up, rubbing his neck and gazing sideways at his pupil, glad of the sudden space between them.

"So… does it help us at all? Is there something new?"

"Perhaps". The boy started pacing again, his hands behind his back. "The height and amount of force used match the previous rape, so I don't think is ventured to attribute this crime to the same attacker."

"Of course it's not!" Sherlock glared at him. "Excuse me, go on!"

"The same attacker… A Greenwood student. But now he had the prevision of wearing a mask, and doing it in a safer place… The second floor toilets, at lunch time? Who would go there?"

"Do you think he asked the girl to meet him there?"

"Could be, yes. What is clear is the fact that, this time, he planed the attack. With Claire, he was just testing the waters, now he knows exactly what he wants to do. And he has no qualms in using the violence to achieve it. Claire was the first and… Oh!"

The boy stopped his pacing and his words all of a sudden.

"Sherlock? What happens?"

"I know who the attacker is!"

And with these words, Sherlock ran out the door. Startled, John followed him, trying not to make too much noise in the silent corridor. The boy had run to the lockers, located at both ends of the corridors, and was now opening his. He took his schoolbag out and searched inside for a moment. He finally handed John a copy of the suspects list he had worked out.

"How could I be so blind, John? It was in front of our noses all this time…"

John took a look at the list again, still puzzled.

"Sherlock. Could you please explain…?"

"I have already done it!" Sherlock pointed to the list again, impatient.

"OK, excuse me for being slower than you!" John exclaimed, annoyed. Then he realised they were still in the corridor, while the rest of the people were inside the classrooms, working, and lowered his voice. "What am I missing?"

"Isn't it obvious, John?" Sherlock snorted. "The attacker is in Claire's group, in MY group. He watched her every day, that's why he chose precisely Claire. Possibly, he didn't even ask her out or anything; he just watched her flirt with a lot of boys and got angry."

John went again to the list, searching greedily. There was only a name of the list that belonged to Sherlock's group. He raised his eyes again from the paper; Sherlock was looking at him, intensely, his eyes green this time, with a touch of yellow that made them look like if his eyes were in fire.

"Simon. Do the rest of features match? I didn't know he practised any sport…"

Sherlock shook his head.

"No, but he helps his father in the afternoon. His family runs a meat warehouse. Lots of carrying heavy boxes, perhaps even using the cleaver… That makes do for the rough hands. And he is strong, as tall as me…"

"God, he is twice your size! His voice is not exactly deep, though."

Sherlock shrugged.

"Claire said he had something over his mouth. His t-shirt, perhaps. And he has certainly changed his voice."

"Alright." John sighed, his head spinning. "So, we know who the attacker is. What can we do now? Should we try to convince Gregson that we have found the man?"

Sherlock frowned and started pacing again, rubbing his lips with his fingers.

"He would never listen to us! God, I need a cigarette!"

"Let's go out of here. You are not going to the next lesson either?"

Sherlock grinned and took his schoolbag, as if such a silly question didn't deserve an answer. John found himself following him again, this time down the stairs and out of the building. As soon as they arrived to the front stairs, outside, Sherlock produced a cigarette from his coat pocket and lighted it.

"Ah, that's better!"

John stared at him, frowning.

"Sherlock, you know you shouldn't smoke, right?"

Sherlock dedicated him a lopsided grin.

"Yes, teacher. Can we go back to our more interesting topic of how to find evidences against Simon Wells?"

John sat on the first bench of the school ground, sighing. He felt suddenly rather impotent; how could it be possible, that they knew who the rapist was, but nobody was going to believe them? Not when their hands were empty. They needed evidences, something tangible that Scotland Yard would accept. That seventeen year old criminal was right now sitting in his classroom, looking all innocent and smiling innerly at how clever he was. Oh my God. Marcie and Nell and the rest of the girls of the group… They are all in danger until we can put him in jail!, he thought.

"Relax, John". Sherlock's voice interrupted his thoughts. "He won't attack any soon. He needs time to pick his next victim and plan it all".

John nodded while a chill ran across his back.

"Until all the school has relaxed", John said. "That's when he will attack again."

"At this time of the year, that means after Christmas. So we have almost a month to plan how to set him a trap."

Sherlock turned suddenly, his long coat snapping the air, and started to walk with long strides towards the grounds exit.

"Hey! Sherlock!" John ran after him, cursing. "You can't be sure about that! What if he has already picked a victim? What if he doesn't want to wait?"

Sherlock threw the cigarette butt, exhaling a last puff of white smoke.

"Both attacks have been inside the school, I doubt he will attack during the Christmas break. He has found his modus operandi by now, he won't deviate. We should keep an eye on him until the holidays begin. That would make you feel better?"

"Well, yes."

John stopped at the gate, slightly breathless for trying to keep up with the young man's strides. Sherlock didn't turn this time, just kept walking fast, his schoolbag hanging loosely from his shoulder, and waved him with his free hand.

"See you tomorrow, Doc!"

The next ten days passed in a blur. Sherlock and John compared their timetables and reckoned that it would be slightly difficult to watch Simon Wells during all the school hours, being just two people, so John proposed enlisting Rick, Marcie and Nell for the surveillance; after some insisting, Sherlock grudgingly accepted. John didn't say it, but it made him feel better knowing that the girls were aware of who was their main suspect. His students were shocked by the news, but they joined with enthusiasm. So promptly there was always someone waiting for Simon Wells at the outer gate, leaning against the wall while playing with their phones, or pretending to tie their trainers. Someone followed his very movements on his way towards his classroom. When he went to the toilet, someone raised their hand after a minute and asked to go to take care of an "emergency". Same with every break and lunch time. Simon Wells was thoroughly watched until he disappear streets away from Greenwood every afternoon.

"He doesn't seem to pay any attention to girls", Marcie commented at lab hour. Simon was in the other half-group, where Rick was keeping an eye on him, so they could talk more freely.

"It doesn't mean anything", Sherlock pointed out. "It is possible that he has already chosen a victim, even that he chose his victims weeks or months ago."

"Always SO reassuring, Sherlock", Marcie snorted.

"Did you manage to talk to Saskia's friend, Nell?" Sherlock asked, ignoring Marcie. She frowned and attempted a poke at him, which he dodged easily without even looking at her.

Nell nodded.

"Yep. You know she was just fifteen?" John grabbed the table tighter, feeling goose bumps down his back. What a sick bastard; the poor little girl. Nell sighed and kept talking. "You were right, Sherlock: Saskia received a note from a secret admirer, asking her to meet him at lunch time at the second floor toilets. But the note also said she must burn the note as soon as she had read it."

"And she did", Sherlock mumbled, biting his lower lip, his eyes glazed and lost in his own thoughts.

"Sadly, yes", Nell confirmed. "I still can't believe it, she's so… small. Are you sure about our suspect, Sherlock? Because I'm tempted to steal my father's hammer and sculpt a new face on that monster."

"We need evidence, but yes, ninety per cent sure."

"What if he attacks someone during the Christmas break?" Marcie asked.

Sherlock sighed, and John could tell he had already disconnected from the conversation. 'Boring', he would say. Because they had discussed about that again and again; Sherlock was sure that scenario wouldn't happen, but of course the rest had their doubts. They all agreed Sherlock was a genius, but all those policemen around the school made the students grumpy; and the staff wasn't very happy, either.

The Christmas break couldn't come too early.

But the first day of holidays arrived at last, and they were really happy to leave the uneasiness behind Greenwood's walls. John thought that, first of all, he was going to make up for all the lost sleep of the last weeks. His phone chiming at eight a.m. broke that idyllic plan.

He grunted and reached for his damned phone, and then tried to read the whatsapp sender through his still half closed eyes. When he managed, all the sleep dissolved at once.

'Did you tell me I could whatsapp you if I had any news of S.? SH'

John hurried to answer.

'Yes, of course!'

'Can I whatsapp you even if I don't have any news of him?' SH

John giggled. That stupid, stupid genius…

'I think that's exactly what you are doing right now.'

'Alright. Good to know.'

And that was all for the day. The next day was Christmas Eve, and John took the train northwards and met his parents and sister for dinner. Everything was fine, or at least they pretend it was. They ran out of topics to talk about very soon, though, but his mother had the brilliant idea of taking out their family photo albums. His sister, Harry, and him obviously protested, but a punch and an album later they were laughing like little kids, and the house-made dinner filled the whole house with a delicious smell. His phone buzzed, and John fished it from his trouser's back pocket.

'My brother is still more insufferable than I remember, and my mum has burned the goose. Send help!' SH

John smiled lazily.

"Oooh, is there a girlfriend, then?" Harry smirked.

"Sadly, no. Just a pupil."

"Now you give your phone number to your pupils, John?" his sister berated him, frowning. "Isn't it against ethics, or something like that"

John felt slightly ashamed, remembering too well some of his feelings about Sherlock, until he reassured himself, claiming that the main reason he had given Sherlock, Rick and the girls his number was a cent per cent honest reason.

"That's none of your business, you busybody."

But he pocketed his phone without answering the message. At midnight, though, after they toasted and wished the best for each other, he took out his phone again and sent a quick:

'Happy Christmas, Sherlock! I hope you are having a nice evening after all'

The answer arrived less than a minute after:

'Honestly, it would be much better if you were here' SH

John's heart skipped a beat. His phone, still in his hand, buzzed again.

'Sorry, happy Christmas to you too' SH

Sherlock was silent on Christmas and Boxing days. John was aware of it because he began to have the habit of checking his phone for messages every five or ten minutes. The 27th he couldn't help it any more.

'Have you checked the news? Anything that seems related to S.?' he sent.

The answer, as always, was fast as light.

'Yes, I have, and no, anything at all. SH'

And thirty seconds after:

'The most boring Christmas I can remember in years. SH'

'Sorry to hear that. Any good present?' John asked, smiling at his phone.

'Ppppfffff. My mum gave me one jumper that matches those horrible ones you wear sometimes. SH'

'Oi! Don't insult my jumpers!'

'By the way, your mother and mine could meet and become friends: mine also gave me a jumper'

'Oh, not another one. SH'

'Yessssss… Put yours on the first day of school and we will match.'

'No way I'm wearing that. It's simply distasteful. SH'

'Isn't it always, when our mothers pick it? Got a pic of the offensive jumper?'

A full minute after, a pic arrived: a green angora wool jumper with turtle neck.

'Not that bad, but yes, not your style. Wanna see mine?'

'No. SH'

Oh, John thought. Fun is over.

'I prefer to see it when you are wearing it. SH'

John tried to think of what to say to that. He thought about it for five full minutes, and his phone seemed to weigh more in his hands every minute that went by. At last the device buzzed again.

'Aren't you going to tell me off for the innuendos? How unusual of you… SH'

That's enough, John thought, sweating.

'Can you please stop it? We will talk back in the school,'

'That's what I expected you to say. I'll text you if I hear something about our suspect. SH'

John sighed and pocketed his phone.

He kept checking it from time to time, more sparingly now, but no more messages from Sherlock arrived.

He attended a New Year's Eve party with his friend Bill, and at midnight, when all the couples kissed and the fireworks turned the dark sky into a golden and fabulous landscape, he typed a fast 'Happy New Year, Sherlock' on his phone. But when he was about to send it, he remembered at once the previous days' conversations and preferred to delete it.