Dudley was not having a good day. It had started early that morning, when Hedwig had delivered one of Harry's letters. Piers had woken up unexpectedly, and almost seen her rapping on the window.

Thankfully, Hedwig had been smart enough to hide from him, and instead, Dudley had had to explain why he was standing next to the open window before it was properly morning even. Piers had looked at him suspiciously as Dudley had stammered something about fresh air, before going to the bathroom.

As if that scare had not been enough, the owl had decided to fly past the window during his maths class. Of course everyone had noticed her, and their teacher had to go on and draw even more attention to her, calling it an 'unusual sighting', and saying how odd it was to see a snowy owl in England. How he even knew that, Dudley had no idea. But it certainly was inconvenient, and he decided to sneak out of school as soon as classes were over and find her, before there were any more 'unusual sightings'.

Harry's letter had contained more details about the magical object hidden at Hogwarts, and his cousin's suspicions that one of the teachers was trying to steal it. What had been a vague and curious tale in the last letter, when Dudley had been sure that Harry was mostly exaggerating, now seemed like a serious issue. A potentially dangerous, serious issue, and there were not one, but two teachers who might be involved.

It had given Dudley an uncomfortable feeling, reading that. He had reassured himself that he was not starting to worry about his cousin, of all people, but he had finally admitted to himself that the letter bothered him a little after all.

Piers had found him outside shortly after, and had been even more suspicious of his behaviour. It had not helped that Dudley had quickly tucked Harry's letter away. Piers had only seen him quickly pull his arm back and look guilty, but that had been more than enough.

However, all of that would have blown over, had they not come across Arthur – Artie – on their way back to their dorm, eagerly talking to one of their teachers. As soon as the boys were among themselves, Piers started with the insults, calling Artie a suck-up and nerd, and asking him what he was so happy for, talking to a teacher.

Dudley found it rather amusing to see the scrawny boy twitch, and try to mumble some answers. But when Piers grabbed for his notes, and then pushed Artie away when the boy tried to take them back, Dudley stepped in to stop his friend.

This was not the first time he had found himself doing that of late. Dudley was not sure what compelled him to help Artie, but something about seeing the scrawny boy being pushed around did not sit well with him. Piers refused to be distracted from what he was doing, however, as he had allowed Dudley to do the previous times.

"Come on, Dud, I'm having a conversation with Artie here."

"You had the same conversation with him the day before yesterday," Dudley reminded him.

"And you interrupted us back then, too. But we really ought to finish our chat, huh, Artie?"

"I-I-" the boy stammered, and pushed his glasses up his nose.

The gesture struck Dudley as familiar. He was reminded of another scrawny, bespectacled boy who tended to do that when his ill-fitting glasses slid down his nose; who also had had to endure similar conversations with Dudley and Piers and their other friends back in Surrey; and who was now studying magic in the wizarding world where he was famous, and chasing criminal teachers in his spare time.

"Piers, let it go," Dudley said tiredly, wishing that line of thought to leave him. "Come on, let's see if the computer room is free. We haven't played Mega Mutilation 2 in-"

"I don't care about that stupid game," Piers shot back. "What is with you, are you going soft?"

Dudley flexed his fists. "Say that again."

Piers took a half-step back. "Well, what is it, then? I just want to find out what important business Artie here needed to discuss with a teacher. Before the holidays, you'd have had a chat with him long before I'd even thought of it-"

"I don't think you need to bully him for that-" Dudley said impatiently, thoughtlessly.

He did not finish the thought. Silence followed as soon as the words were out. This was the first time Dudley had referred to what they were doing as bullying, and as soon as he had spoken, he felt a line had been crossed.

"Look, Piers. Let's just do something else," Dudley attempted to save the situation. "If you don't want to play Mega Mutilation, we could go and spy on the older boys. We still haven't found their new smoking spot, and it's been over two months since the old one was-"

"Forget it. I've no time for your lame ideas." With that, Piers walked out of the room, past Dudley, who half-heartedly tried to turn him around, but the other boy brushed past him and was gone.

The remaining two boys stared at each other. Artie could not hold Dudley's gaze for more than a moment. He looked down and began to fidget. Dudley looked away. His oldest friend had just walked away from him, and he still was not sure what he had made all the fuss about. He shot another glance at Artie, and then slowly started walking towards the door himself.

"You dropped your letter."

Dudley stopped in his tracks at the softly spoken words, and turned around. Artie was picking up Harry's letter from the floor, and flinched away as soon as the bigger boy took a step towards him.

Dudley could no longer see what about Artie had reminded him of Harry. True, both boys were skinny and wore glasses, but that was where all similarities ended. Artie looked plain, nerdy, and was almost as blond as Dudley himself. There was none of the energy and coordination that made Harry such a difficult target to catch. Beyond the physical, the differences were even more obvious. Artie had none of Harry's cheek or wit, but instead spoke slowly, softly, and mostly when he was spoken to. Except in class. And he was easy to frighten.

"Give me that!" Dudley took the letter from the other boy's hand none too gently, the fear of discovery suddenly turning all his jumbled emotions to anger towards Artie.

"I-I didn't read a word."

"You better not have!" said Dudley, tucking the letter away in his pocket. "Can't a bloke keep his letters from his family private," he added defensively.

Artie choked off a retort and glanced sideways.

"What!" Dudley demanded to hear it.

"N-nothing."

"Spit. It. Out."

The intimidating tone worked this time. "It's pretty obvious that letter's not from your parents, isn't it?" Artie asked meekly, trying to make himself smaller.

Dudley fought down panic as silence fell after those words. "Of course it's from my parents. Who else would it be from?" he said after what he felt had been a noticeable pause.

Artie did not answer.

"How is it obvious?" asked Dudley, unable to deal with the silence.

"W-well, the paper's different. It's just plain lined paper from a notebook, or something. Not like the fancy paper your mum uses. And even your dad writes on blank sheets, doesn't he? And the handwriting doesn't look like it's from a grown-up." Artie stopped for a moment, then went on. "And I know you don't have any siblings. You and Piers know each other well, and you mention his sister once in a while, but you've never mentioned-"

"Shut up!" Dudley had heard enough. He had been so careful, and now it seemed some things had been fairly obvious despite that.

The boys stared at each other in silence, assessing the other.

"I'm not going to say anything," offered Artie.

"I – It's no big deal! They're from my cousin." Dudley gritted his teeth at Artie's facial expression. It was clear he was not accepting the explanation, even though he was trying to pretend he was.

"My parents don't like him, that's why..." Dudley tried to explain.

"They don't get along with his parents?"

"His parents are dead."

"Oh. So they dislike the people who are raising him? Who does he live with-"

"Stop asking stupid questions!" Dudley finally reached the end of his patience. Only after hearing himself speak the words, did it occur to him that he sounded remarkably like his parents, giving the standard response to any and all of Harry's questions.

Chastised, Artie laid off, and snuck away towards his corner of the room. Dudley would have liked nothing better than to have stormed out of the room at that point, upset as he was. Instead, he had to lie down, because he suddenly had a splitting headache.

~HP~

Following the quidditch match in February, the trio decided to investigate Snape and Quirrel some more. But they soon learned that that was no easy business. They tried keeping an eye on the third floor corridor, but neither professor seemed to be lurking around there. On the whole, nothing suspicious was happening.

On top of that, Snape still seemed to be everywhere Harry was, and even Quirrel kept shooting them sideways glances whenever they spotted him in the corridors.

Before they knew it, March had passed, as well, it was the last day of the month, and the Easter holidays were to begin in a couple of days. On top of that, both of Harry's friends had opted to stay, much to his joy.

"We should have been more careful. We shouldn't have let them become suspicious," moaned Hermione that evening, after their last trip to the third floor corridor for that day.

"Too late for that," was Ron's best shot at reassuring her.

"We have to think of something," said Harry. "We're no closer to deciding which of the two is after the stone."

"Well..." Hermione fell silent, and chewed on her lip. "Maybe we could try asking around."

"What?" exclaimed Ron. "Last time I suggested that you thought it was a barmy idea!"

"When was that?"

"In December. Don't you remember? When Harry wanted to know how to buy presents-"

"Oh, don't be silly, Ron," interrupted Hermione as soon as she remembered what he was talking about. "That was completely different. I just said asking that sort of thing might be awkward-"

"What, and asking people which of our professors is more likely a criminal isn't?"

"That's-" Hermione began hotly, but Harry interrupted the bickering.

"I think it's a good idea, Hermione," he said. "We just need to get an idea what people think of them, and what they know about them. We'll need to be careful not to make anyone suspicious, of course-"

"Yes, that's what I meant." She shot Ron a smug look. "No direct questions. We just need to get people talking about those two. The older students, and maybe even the other professors. But we'll need to be extra careful with them."

Having decided on a plan, even if it was not much to go on at that moment, Harry became aware of the other occupants of the common room once again. There was Percy, talking loudly, and gesturing with his hands, trying to get the twins to pack. Fred and George were the only Weasleys leaving for the holidays, having decided that they did not need the extra studying. Harry was only half listening to them annoy their older brother with evasive non-answers, until he heard someone's birthday being mentioned.

Ron looked up, and then looked away again. Harry got suspicious.

"Is your birthday coming up?" he asked.

"What?" Ron looked surprised. "No."

"Whose birthday is coming up?" Hermione, who had already begun working on one of her essays, looked up. "Yours, Harry?"

"Er, no."

"Hah! Hermione, how can you get Harry's birthday wrong? What happened to all the books you read about him?"

"Oh, right." Hermione grew red. "It's in July, isn't it?"

"Er, yes."

"So is it Ron's birthday, then?"

"That's what I was asking."

"No, it's not. It's ours," said one of the twins, who had walked up behind them unnoticed. "Or will be in-" He looked at his watch.

"Four hours," supplied the other twin. "Ron's birthday was a month ago."

"Oh, we didn't even know," said Hermione, sounding disappointed.

"Don't worry. We all forget it as well," said the twin that Harry was almost sure was Fred.

"Figures," said Harry in sudden realisation. "Of course your birthday would fall on April Fools' Day."

As soon as he saw the lack of recognition on the twins' faces, he knew he had made a mistake.

"April Fools?" asked Fred, who had become interested as soon as he had noticed Harry flinch.

"So, Hermione, what's April Fools' Day?" asked George before Harry had the chance to come up with an explanation.

Hermione started explaining before she could think better of it, her need to answer every question correctly winning over her common sense. She had blurted out all the important details before she could rein in her tongue.

"That's a very interesting day muggles have there. What do you say Fred?"

"You're right, George. A truly excellent day. Of course it was bound to be our birthday."

"And we didn't even know until now."

"Never got to celebrate it."

"And we only have a few hours-"

"To plan this year's celebration-"

"To make up for all the times we didn't know."

"Thanks, Harry!" they said together, and walked off, whispering excitedly.

"Yeah. Thanks, Harry," said Ron darkly. "You, too, Hermione."

Both friends cringed.

~HP~

The next day, long before sunrise, Harry had another gruelling quidditch practice. He was woken up far earlier than expected, by a frantic and confused Oliver who insisted they had overslept and that the others had already started practice without them.

Once they arrived on the quidditch pitch, Harry's suspicion turned out to be correct. The twins had started early with their peculiar celebration of their birthday. They had woken up Angelina – which in itself was a questionable thing to do, as boys were not supposed to enter the girls' dormitories – and told her that Oliver had gone mad and ordered training extra early. Alicia, who shared her dorm, had suffered the same fate. While the girls had been convinced to look for Katie as well, the twins had started on on Oliver himself, telling him that he and Harry were late for training, and that the others had already begun training.

The twins' lies were uncovered quickly enough once they were all on the pitch, but Oliver decided to go ahead with the training, seeing as they were already there. The twins did not stop there, though. Even though everyone was ready to kill them by then, they kept trying to mess with Oliver's head, trying to convince him that he was confusing the dates for their quidditch pitch bookings, and even the date of their next match. They kept at it until Oliver actually started doubting his memory, even though his obsession with the game made that almost impossible. As a result, they had to endure the hardest training they had since before their last match.

"What a training. I'm exhausted. I thought we started training this hard to survive Snape's refereeing," said Harry.

"Hush, you. I don't want to hear any of you slacking off," said Wood. "Now that we actually have a chance to win the Cup-"

The others followed this up with protests, shooting Harry sympathetic looks.

"Don't worry, Oliver. If we could win with Snape refereeing, the next match should be easy enough," Harry tried again, remembering his discussion with his friends the evening before.

More protest followed from Oliver, and now Harry received some exasperated looks from the others.

Then, finally, Angelina picked up the topic of Snape.

"Don't worry so much about Snape, Harry. I know, he's not easy to deal with at the best of times, and he really doesn't seem to like you. But he's yet to make good on any of his nastier threats. Dumbledore sees to that."

"He does threaten to poison us every year, though," muttered George.

"He threatens everyone, but with you two, he might actually try," Angelina shot back.

That was a sharper comment from her than usual. She obviously still was not over that morning's prank from the twins.

"Don't sound so happy about it, Ange," said Fred. "You know you'd miss us."

"Nah, he wouldn't dare," said George.

"Because if he did-" went on Fred.

"We'd have to take revenge."

"Nasty-"

"Fabulous-"

"Unavoidable-"

"Unbeatable-"

"Twin revenge!" they finished together.

"Oh, haha. Yeah. Snape's afraid of your revenge. I'll believe that in a minute," said Angelina, trying to sound condescending, but could not keep a smile off her lips.

"Tsk, tsk." Fred shook his head. "Ye of little faith."

"We know things-"

"And dare things-"

"No one else does," the twins went on conspiratorially.

"Really. Like what?" asked Harry.

"No. Harry," said Angelina. "Don't give them the satisfaction-" But she was too late.

"Now that's the question, isn't it?" Fred slung his arm around Harry's shoulders. "You understand of course that we cannot tell you."

"We can't just give you-"

"Our best secrets."

Harry decided at this point he was unlikely to hear anything useful about Snape and tried to extricate himself.

"Sure. I believe that." He shook his head, and stepped out from under Fred's arm. "You have secret weapons against Snape."

He received two identical indignant looks from the twins. They exchanged a look that seemed to communicate a great deal.

"I see you don't believe us."

"We're hurt, Harry-"

"Disappointed-"

"Yeah, yeah, all right." Harry tried to step past them into the changing room.

"I see we'll need to offer a little evidence. What do you think, Fred?"

"You're right, George. No one has faith any more, these days." Fred sighed dramatically. "But he did tell us about this glorious day, our birthday."

"Evidence? What sort of evidence?" Harry was aware he was being toyed with, but he could not help his curiosity win over.

"Now he wants to listen. What should we tell him, George?"

The other twin thought for a moment. Then his eyes brightened, and he motioned Fred towards him to whisper something in his ear. Both twins looked at Harry with rather scary smiles.

"So, er, what is that scary weapon you have against him?" Harry chuckled nervously.

"It's just one word-"

"And don't ask us to explain-"

"Because we're not going to tell you more, no matter what you say."

They paused dramatically, but Harry resisted the urge to ask again.

"It's 'Marauders'," Fred finally said in an almost reverent whisper.

"Marauders? What's that?"

"Shh." George looked around, as if scared of being overheard. "And it's not 'what'. It's 'who'-"

"And that's more than you need to know."

"If you decide to use it-"

"Do it sparingly-"

"Carefully."

"Because we promise no other human being ever turns as purple as Snape does at their mention."

The twins dissolved into rather evil-sounding cackles, and Harry decided it would be safer for him if he made himself scarce just then.

~HP~

It started out slowly, with a misdirection here and there, rumours spread about cancelled classes, while professors were delayed with unexpected summons to the headmaster. But over the course of the day, the chaos wrecked by the twins piled up, and people started to notice.

It all came together in the Great Hall during lunch. The professors were all crowded around Dumbledore, demanding to know why he had disrupted the day's lessons, several students were being accused, who all kept pointing their fingers at other people, and it took a while until the source of all the spread rumours and false information could be determined.

Once the twins' names came up, the jig was up. The boys started shouting April Fools, until Snape interrupted them, and began to shout at them himself, demanding they be expelled. Dumbledore, though, was more amused than angered, and let the Weasley boys explain. As one who knew him might have expected, he found the idea of April Fools' Day amusing rather than annoying. He even agreed that it should be celebrated, much to the other professors' horror.

After the twins mentioned that, on top of that, it was their birthday as well, all the professors had also been won over, even McGonagall. Only Snape's dark glower promised retribution.

Quirrel, Harry noticed, was conspicuously absent.

Harry had been telling his friends about his attempt to talk to his quidditch teammates about Snape over lunch before the twins' antics drew their attention. He had just started telling them about Fred and George's 'secret weapon' against their least favourite professor.

"Yeah. I wouldn't trust them to tell you anything useful," said Ron sceptically.

"I agree. It was probably another April Fools hoax, and the word doesn't mean anything to Snape at all."

Hermione's comment was followed by another bout of outraged shouting from Snape at yet another cheeky comment form one of the twins.

"Yeah... Or it might work too well," said Ron, and all three friends giggled.

Harry and his friends were not ones to give up easily, and over the course of the next weeks they tried their best to find out more about Snape and Quirrel from the other inhabitants of Hogwarts. They had to admit, though, that things were not going too well.

It was not easy to find an excuse to talk about a teacher to begin with. The only topics the three could think of were either complaining about Snape's treatment of his Gryffindor students, or making fun of some of Quirrel's more ridiculous behaviours. Hermione was not comfortable with the first, and none of them were comfortable with the second. Making fun of people's stutters and fears did not usually sit well with them.

The worst part, though, was that none of it was helping. People agreed with them on Snape, and laughed about Quirrel, but no one was telling them anything new.

"Maybe we should try the professors, after all," said Hermione after another useless attempt.

"And how do you want to go about that?" Ron was quick to point out the flaw in her plan.

Hermione had no answer for him.

Weeks passed, the Easter holidays came and went, and with Hermione around, that meant a lot of studying to prepare for the exams which were still months away. With all the studying she was forcing upon them, the boys would have been surprised to learn that she still had time to think of something else. She did. It was just that nothing she could think of seemed likely to work.

It was only after the holidays, when Professor Flitwick mentioned disillusionment charms in class that Hermione finally thought of a way to discuss Snape and Quirrel with another teacher.

Harry had received a letter from Dudley telling him about his troubles with keeping their correspondence secret and decided to seek some help. He approached the front desk after class.

"Er, Professor, can I ask you a question?"

Hermione and Ron, who were almost out the door at that point, looked back. Harry saw them drag their feet in the doorway, but finally they stepped back into the classroom so they could hear what Harry had to ask.

"Of course, Mr Potter. Go ahead," Flitwick said amiably.

"Er, it's about that disillusionment charm, Professor. I was wondering, would it be very difficult for me to learn it?"

"Mr Potter, I'm delighted with your interest in the subject, but I fear that particular charm might be a bit advanced for a first-year. Oh, but if you're concerned about keeping your things secret here at Hogwarts, there's far easier ways-"

"No, it's not that." At Flitwick's s surprised look, Harry proceeded to explain. "It's my cousin, Professor. He's a muggle, and he's at another boarding school right now. He knows of course that I'm a wizard, but no one else at his school is to find out. Just before the holidays, he wrote that some people at his school had spotted my owl. I mean, that's no big deal, but-"

"No, no. That is a serious concern, of course." Flitwick frowned, looking far more concerned than Harry thought his story warranted.

"No one saw much of anything," said Hermione, who had walked over to stand next to Harry. She, as a muggleborn, had received far more serious warnings about keeping the magical world secret, and knew better that everyone took any breach of the Statute of Secrecy very seriously.

"It's just that Hedwig is a snowy owl, and she gets noticed easily," said Harry.

"Yes, I see." Flitwick took on a thoughtful expression. "I know this might be a little more trouble," he began after a little pause, "but couldn't you ask your aunt and uncle to forward the letters by muggle post?"

Harry could not think of a good reply, and was about to turn away in disappointment, when Flitwick shook his head.

"No, that won't do, will it? No, eleven-year-old boys don't want their parents interfering, do they?" Flitwick fell silent again. "Hm, there might..." he muttered. "I might have an idea. Let me think it over until our next class, Mr Potter, and I'll see what I can come up with."

"Thank you, Professor."

"Oh, Professor, he doesn't want to be any trouble," Hermione said unexpectedly.

"I – What?" Harry looked at her, hoping for an explanation, but instead, she stepped on his foot quite firmly, and smiled at Flitwick.

"It won't be any trouble, Miss Granger. I'll just have to see if I can modify the spell slightly, make it easier-"

"Oh, but – but you'd need to work that out. It wouldn't take you any time at all, I'm sure," she added flatteringly, "but maybe we should ask someone else? Do you think there might be some potions that do a similar thing? Or maybe some defensive spells..."

Thankfully, Harry's brain caught up with what Hermione was trying to do, before he turned to her and asked her whether she had gone mad.

"Hmm..." Flitwick rubbed his chin in thought. "I'm afraid I've never heard of such a potion. You could ask Professor Snape, I suppose," he added doubtfully, "but...Oh, well, if it can't wait, and you really, desperately need – I mean, of course you could ask him.

"As for defensive spells – I'll let you know I used to be a duelling champion when I was younger. I do have some idea what defensive spells are out there. Disillusionment charms actually belong to that category. It's just that, with the way Defence Against the Dark Arts has been taught in previous years, I prefer to cover it in my class."

"Professor Quirrel doesn't teach it?" asked Harry, trying to get him to tell them more about his colleagues.

"He – I don't know. He's only started teaching the subject this year. The professors we had in previous years – none of them lasted very long, you see? Teaching that subject has been a bit – sporadic."

"We do a lot of reading in his class," supplied Hermione. "A lot of bookwork."

"That hasn't changed, I suppose. That's how he used to be as a muggle studies professor."

"He's changed, then?" asked Harry, holding his breath, trying not to show how much he was interested in the answer.

"You could say that." Flitwick frowned, clearly unhappy with something.

"He seems very – concerned with safety," Hermione said carefully. "There are rumours he ran into something he couldn't deal with, when he was travelling last year-"

"And yet he seems to have grown far more powerful than he used to be," mumbled Flitwick, almost thoughtlessly. He visibly checked himself as he heard himself speak the words. "That is to say, he seems to have used that year well to advance in his new subject. So maybe you're right, and asking him might be a good idea. I've noticed him use an obscure charm once or twice, so it's entirely possible he might know some spell that might help you that I don't know of."

They thanked the professor and left, almost unable to keep their excitement restrained until they were out of sight. Ron, who had waited by the door, was almost bouncing on the spot at that point.

"Merlin, Hermione, that was brilliant!" he said, barely out of Flitwick's earshot.

"Yes, well done, Hermione," Harry added quietly.

Hermione glowed from all that praise, fairly red in the face, and squealed – just a little bit.

They did not have much time to discuss their new-found knowledge, because that afternoon, they encountered Hagrid in the library, and found out about his new pet dragon – which gave them an entirely new thing to worry about.