A.N.: I set this story in the Marauders era, and I basically slotted the Sherlock characters into various houses and years:
Sherlock: Fourth year Ravenclaw
John: Seventh year Gryffindor
Molly: Third year Hufflepuff
Mike: Third year Hufflepuff
Jim: Third year Slytherin
Sebastian: Third year Slytherin
Donovan: Sixth year Slytherin
The Marauders and Severus are in their fourth year.

Warnings: Bullying, mentions of child abuse

Chapter 1 – Professor Boaz

The crate rattled ominously on the floor of the Defence Against the Dark Arts classroom as the third year Hufflepuffs and Slytherins filed in. The chairs and tables of the classroom had been pushed to the sides, and the crate sat in the centre of the classroom where the front of the aisle would have been. Professor Boaz – a young, pretty woman who had taken on the feared job of Defence Against the Dark Arts teacher back in September – stood behind the crate waiting patiently for her students to enter.

Molly stood near the back of the room, eyeing the crate suspiciously. She had a pretty good idea of what was in there, and the thought made her a little more than slightly apprehensive.

"Good morning," Professor Boaz greeted the class with a warm smile. The Hufflepuffs returned the greeting; the Slytherins mumbled and grumbled. "Who can tell me what is in the crate?"

A few hands shot up, including Molly's, though she desperately hoped that she wouldn't get picked for fear of getting the answer wrong.

"Molly?" Professor Boaz asked, her voice friendly and unthreatening.

Moly gulped in embarrassment. She took a moment before answering. She looked away from the crate and Professor Boaz, and saw Jim smirking at her from the front of the Slytherin crowd across the classroom. He was almost willing her to make a fool of herself.

"I-is it a Boggart?" she offered.

Professor Boaz smiled. "Yes, it is. Ten points to Hufflepuff."

Molly relaxed and shot a triumphant look across the classroom at Jim, who looked as though he had just swallowed a bogey-flavoured Bertie Botts Every-Flavour Bean.

She settled into the lesson after that. Professor Boaz asked individual members of the class about what they knew about Boggarts: why they were Dark creatures, why this one was living in the crate in the first place, and the incantation for the Boggart Banishing Charm.

Fifteen minutes into the lesson, however, Professor Boaz told them all to get out their wands, for they would be attempting the spell themselves. She instructed them all to get into a line and she would release the Boggart so that they could face it one-by-one. The students began to move and Molly, nervous and desperate to get this out of the way, took a space about ten students from the front of the line.

"Ready?" Professor Boaz asked the class. A collective nod went down the line; Molly stayed perfectly still. Professor Boaz opened the crate, and a swirling mass emerged.

Jim – who was at the front of the line – looked up at the Boggart, mystified, while the Dark creature seemed confused as to what form to take. He lifted his wand confidently and cried, "Riddikulus!" There was a massive crack and the Boggart seemed to falter slightly as Jim – cheered on by his fellow Slytherins – sauntered to the back of the line.

The next few students took on the Boggart reasonably well; each managed to get rid of the Boggart on their second or third tries. There were snakes, spiders, clowns; Mike – who wanted to be a Healer – had a dead body on the floor (he later explained to Molly that it was a patient whom he had been unable to save).

The success of others buoyed Molly up for when she reached the front of the line. The previous Boggart – a vampire with its blood-covered fangs bared – transformed into the image of a man she knew very well, who then began to bellow loudly at her.

Molly froze. Her wand hand stopped mid-movement as she stepped back slightly from the form before her.

"Come on, Miss Hooper," Professor Boaz shouted over the Boggart. "Riddikulus!"

Molly – whose hand was shaking – raised her wand. "Riddikulus!" she squeaked. Nothing happened; if anything, the shouting got louder. "R-Riddikulus!" Still nothing happened.

"Riddikulus!" Professor Boaz cried. The Boggart disappeared with a loud crack and, Professor Boaz ushered Molly to the back of the line with a sympathetic look.

Molly, turning crimson with embarrassment, trudged to the back of the line. As she passed Jim, she heard him snickering at her.

"Stupid Hooper can't even get rid of a Boggart," she heard him whisper to Sebastian behind him, who laughed too. Molly picked up her pace as tears began to prickle in her eyes.

~{G}~

After the lesson finished – everyone else had successfully managed to get rid of their Boggart – Molly took a detour to the Great Hall for lunch. She knew of a secret passageway down to the ground floor from Remus Lupin, who was in the year above her; in her second year, she had nearly got in the way of one of the pranks of his best friends, James Potter and Sirius Black, but as it hadn't been intended for her, the Gryffindor kindly dragged her out of the way and into the secret passageway. She was fairly certain that none of the Slytherins knew about it.

She was wrong.

She was halfway down the second spiral staircase of the secret passageway when she heard a familiar voice, one that chilled her to the bone. What was more, it was getting louder.

Molly opted to act normally and try and pass by without too much of a confrontation. She turned the corner of the staircase and came face-to-face with Sally Donovan.

Donovan was a sixth year Slytherin who, for the most part, left Molly alone. It was more the Slytherins in her own year, in particular Jim and Sebastian, who hated her. Yet as she got closer to the Slytherin, she noticed that Donovan had a wicked smile on her face.

"Hello, Hooper," she smiled, in a false tone of friendliness.

"Hello," Molly nodded, standing up as tall as she could. She wondered if she would be able to reach her wand first, if it came to that; yet knowing that she would probably be less than useless in a duel, she wondered if any of the teachers knew about the secret passageway…

"Heard about your little Defence Against the Dark Arts lesson," Donovan sneered. "Can't even get rid of a Boggart?"

Molly gulped nervously. "I-I'm sure I just need some more practice," she said, her voice hollow. Jim and Sebastian's laughter was still ringing in her ears.

"Hmm, practice," Donovan agreed, looking Molly up and down. "I'd be happy to teach you. I remember doing Boggarts in third year; I got rid of it first try, but then, I am a pureblood and I've grown up with magic all my life. Maybe it's more difficult for you Mudbloods."

Spurred on by her hatred of that word, Molly sought to defend herself. "Mike got rid of it, and he's Muggleborn!" she insisted, her voice sounding stronger.

"Oh! So it's not a Mudblood thing, then," Donovan grinned evilly and leaned down into her face. "Maybe it's just you."

Molly's eyes started to prickle slightly as Donovan straightened up. "I-" she began.

"Course, you could always ask the freak for help," the Slytherin shrugged. "If he'll give you the time of day, that is."

"I help him with Astronomy," Molly mumbled.

"Oh, yes!" Donovan nodded, her voice sarcastic. "Yeah, he takes help if he needs it. But he'd never give it. You're wasting your time with that one."

Molly felt winded. "What do you mean?"

Sally smirked. "Everyone knows about your little… crush. It's cute. But it's never gonna happen."

Molly, determined not to cry in front of the Slytherin, pushed passed and headed for the Great Hall as quickly as she could, trying to ignore the cackles from above her.

She would ask him for help, and he would accept.

~{G}~

"Where did you say you found this sludge again?" Severus asked, as he tipped the rich, royal blue gunk into the simmering potion before him.

"On the bottom of Flugelhorn's trunk," Sherlock explained, watching on from a distance.

"Felix Flugelhorn?" the Slytherin enquired, as he readjusted the flame beneath his cauldron with his wand. The Ravenclaw nodded.

"Yes, it was found on the bottom of his trunk which had been emptied of all its contents," he elaborated, jumping out of his seat to stand opposite Severus and inspect the potion. Prior to the gunk being added, it had been a bright pink colour; it had now become a murky brown.

"And you don't know what it is?" Severus looked from the potion to Sherlock with a smirk playing on his lips.

Sherlock scowled. "No," he admitted through gritted teeth. "That's why I need you." He picked up his bag from the table and readied to leave.

Severus chuckled. "And why me, specifically?" He grinned mockingly.

"Because," Sherlock began, tying his scarf around his neck, "you are the only one skilled enough at Potions to get Slughorn to like you enough to let you use the classroom at lunchtime."

"Are you saying that I'm better at you than something?"

Sherlock froze in anger. He turned very slowly back to the Slytherin. "Only marginally," he mumbled; Severus smirked.

The Ravenclaw turned back and began walking towards the door. "Let me know what colour that turns in an hour; a man's alibi depends on it."

He did not turn back to the Slytherin as he marched out of the Potions classroom. His stomach gave an unpleasant twinge, demanding food, but he would not eat until he knew who had emptied Felix's trunk. Nevertheless, there was no headway to be made in the case until he knew what colour the potion turned, so he decided to go down to the Great Hall anyway.

He passed the Ravenclaw table without so much as a backwards glance, heading straight for Gryffindor. Though lunchtime was half over, the table was still pretty much full of students, most of whom were watching the infamous Marauders set up their latest prank. One student, however, was not engaged in the 'entertainment': a blond boy at the very end who ate with considerable gusto.

Sherlock sat down in front of him, and the blond boy jumped.

"Sherlock!"

"John," he nodded. John Watson was a seventh year Gryffindor, and since Sherlock had started at the school three years after him, the two had become friends. Well, Sherlock supposed that 'friends' was the right word. He had never needed such a word previously.

"Why do you keep sneaking up on me?" John sighed, pulling another piece of risotto onto his plate.

"I don't," Sherlock supplied simply. "You just don't observe my arrival."

John rolled his eyes but knew better than to try and argue. "How is the case going?"

"Fine," Sherlock explained. "Nearly finished, in fact."

There was a cheer from the other end of the table. The two boys looked around to see that the Marauders had successfully managed to charm a number of water balloons to fall on an unsuspecting Hufflepuff's head.

Sherlock turned away as the Hufflepuff went passed. John flicked his wand from under the table and dried him off. Not knowing how the effects of the prank had suddenly been reversed, he looked around, confused. He did not suspect that John had anything to do with it, so shrugged off his seemingly good fortune and carried on to his own table.

Sherlock had noticed, though. "Why did you do that?"

John, who had humbly returned to his food, looked up. "Sorry?"

"Why did you help him? He doesn't even know it was you."

"Well," John shrugged. "It was a… good thing to do."

One of the reasons that Sherlock had been so intrigued by John Watson – other than the fact that he had cursed their Defence Against the Dark Arts teacher in Sherlock's first year when the Ravenclaw had discovered that he had been using the Imperius Curse to force students to maim themselves, and was nearly about to do the same to Sherlock – was that he had a strong moral code that Sherlock did not understand. And not understanding was something that he was not used to.

The Ravenclaw rarely paid attention to social expectations, for they were too bothersome and often got in his way. The Sorting Hat had sensed this in him in his first year and had threatened to put him in Slytherin; but Sherlock had protested, for if the Hat were to choose Slytherin over Ravenclaw, it would seem like a slight on his obviously superior intelligence. Lucky for him, the Sorting Hat paid attention to the individual's choice – though when he had told John about this, the Gryffindor had joked that the Hat had given in just to shut Sherlock up.

He studied John carefully. "Maybe I could learn something from you," he smiled.

John snorted and looked up again. "You, learn something from me?" He seemed rather smug at this. "I thought you knew everything?"

"I know everything of importance," Sherlock clarified.

"So knowing good from bad is not of importance?" John asked, his eyebrow raised. Sherlock sensed that this was a trap. He opened his mouth to speak, but was interrupted by a tap on his shoulder.

"What?" he snapped impatiently, turning to the person behind him. It was Molly Hooper, looking like an owl caught in the Hogwarts Express lights. Her eyes were red around the edges – she'd been crying. The hems of her sleeve were slightly frayed – she'd been fidgeting with them, possibly a sign of distress. Her hair was little messy, but too messy to indicate that the untidiness was simply due to her not having brushed it this morning – running?

"I… er…" she squeaked. "N-never mind." She disappeared again, sinking onto the bench at the Hufflepuff table and staring at the table before her, blankly.

Sherlock, slightly confused by this, shrugged and turned back to John.

John was glaring at him.

"What?" he asked.

John sighed. "That would go firmly in the 'wrong' category," he said, harshly. Sherlock blanched. Had he done something wrong? He hadn't done anything…

"What did I do?" he asked, genuinely confused.

"She's upset!" John exclaimed.

"Well, yet, that was obvious. But what does that have to do with me?"

John shook his head in disbelief. "You're joking, right?"

"John, you have known me for four years, you know I never joke." This didn't seem to have helped matters, however, for John still appeared exasperated.

The Gryffindor sighed again. "She was trying to talk to you about it."

"Oh!" Sherlock exclaimed, looking around to the Hufflepuff table and back again. "Why?"

"Honestly?" John asked. "I have no idea. But I think you at least owe her an apology." He gestured to the Hufflepuff table.

Sherlock looked back round. Molly was still staring wide-eyed at the table. Sighing, he pushed himself up and headed over, hearing John rise from his seat behind him.

Sherlock sat opposite Molly, drawing the Hufflepuff's attention. Her cheeks darkened when she saw who had taken the seat, as John sat next to her.

"I have been informed," Sherlock began, glancing at John for confirmation that he was doing this correctly; he was awarded with a swift nod, "that I should have listened to you earlier. Therefore, I am giving you the opportunity to talk. To me. Now."

Molly blinked, half in surprise, half in confusion. She shot John a quick 'is-he-for-real?' look – which was responded to with another quick nod, this time accompanied with an eye-roll – and turned back to Sherlock, who was now glaring at the Gryffindor.

Molly gulped, nervous. "Well… it's just…" She took a deep, shaky breath, and her gaze dropped so that she was staring at the Ravenclaw's scarf, though Sherlock supposed that she was not really seeing it. She then paused. Sherlock was beginning to feel annoyed; if she wanted his attention for much longer, she would have to speak up.

"It's okay, take your time," he nodded reassuringly, flashing a false smile. "But speak quickly." He dropped the smile. John shot him another pointed look, but Sherlock reasoned that as he had only seen it in his peripheral vision, it didn't actually count.

Molly sighed, and closed her eyes briefly. She opened them again and spoke. "I just had Defence Against the Dark Arts with the Slytherins," she explained. "We were looking at Boggarts, and how to get rid of them. But when Professor Boaz brought out the Boggart…" She trailed off. Sherlock's irritation, which had begun to morph into relief when she had finally started talking, now piqued again. He was about to announce his boredom at her silence when she resumed her story. "Well, I was the only one who couldn't get rid of the Boggart. I felt like an idiot."

Sherlock opened his mouth to explain that she was, in fact, an idiot – and that she shouldn't worry about it, because almost everyone was – but was stopped by John. He reluctantly opted to remain silent, which was an incredibly difficult feat for the Ravenclaw.

"I suppose Jim and Sebastian found that very funny," John asked sympathetically. Molly nodded, her eyes brimming with tears. Sherlock began to panic – what would he do if she started crying?

Mercifully, she gulped away the tears. She looked back up at Sherlock. "Well, I was just… wondering, if… if…"

"Yes, yes, spit it out!" Sherlock snapped.

"Sherlock!" John barked.

Yet Molly continued as if the boys had never spoken. "If you would mind tutoring me?"

Sherlock's head snapped back from the Gryffindor to the Hufflepuff. "What?"

Molly sighed. "Would you mind tutoring me in the Boggart Banishing Charm, please?" she asked more clearly, finding it easier now that she had technically already asked once.

Sherlock considered the request for a moment: having to spend time that could be used to solve cases tutoring a girl who could easily practice the charm on her own, most likely having to deal with a hysterical Hufflepuff as she faced her worst fear repeatedly, having to possibly face his own Boggart…

"Boring," he declared in a monotone, and made to get up. John, however, shot him such a thunderous look that Sherlock was almost convinced that the Gryffindor was going to curse him. He slowly lowered himself back down into his seat.

"This isn't a case," the Ravenclaw hissed at John, as though Molly wasn't even there.

"No," John agreed. "But you said yourself that the Flugelhorn case is nearly completed, and you don't have anything else lined up. This is a challenge. It will stop you breaking into Gryffindor Tower and throwing Reductor Curses at the wall," John added in a mutter.

Sherlock glared at him for a moment, before deciding that a challenge – in any form – would be better than having to deal with the mind-numbing boredom of not having anything to do. He slowly turned to Molly, whose eyes were wide in apprehension.

"Molly, I will tutor you," he nodded at her. She began to smile. "Meet me in the Defence Against the Dark Arts room at seven on Thursday."

And with that – without waiting for the Hufflepuff to respond – he swept out of the Great Hall to the Potions classroom, for the final decider in the Flugelhorn case.