A Boys Tail by RiddikuLiss

Following Potter's little "escapade" the other week in the lake- resulting in a last minute rescue on Severus' behalf- the potions professor had since remained vigilant in everything he did.

Well, more vigilant than usual, that is.

He believed he was a careful man, only going for a swim in the lake when it was absolutely vital, and making sure he wasn't seen or followed by any lurking students. He'd kept this act up for years, and to this day not a single soul knew about his 'alternative identity'.

That is, until Harry Potter came to Hogwarts.

Now each opportunity to go for a routinely swim became another opportunity to be seen by the Potter-boy again. Or any other student for that matter.

Because if a complete dunderhead like 'Potter' could find out about him, then so could everyone else.

After their chance meeting, Severus had remained sceptical about whether the boy would keep his word. But to his credit, no word or rumours of large-tailed creatures hiding in the lake had been spread about the castle.

'Yet' he thought with a snarl, as he watched the boy work quietly on his boil curing potion. Both he and Longbottom were useless as ever, and Severus was beginning to regret pairing them together for the sake of his own cruel enjoyment. A melted cauldron was definitely not worth an hour watching two incompetent students flap about like flightless birds.

Which was exactly what was currently happening.

Of course, being a teacher, he had to have eyes in the back of his head at all times. After all, he had fifteen cauldrons to keep track of at once- and thirty heads to observe, making sure one wasn't suddenly blown off its neck by a powerful backfire of a ruined potion.

And with more than ten years of teaching experience, he'd grown quick to spot an accident in the making.

Longbottom had just handed his awkwardly sliced ingredients to the Potter boy, who'd stirred the mixture a total of SEVEN times CLOCKWISE, rather than the required counterclockwise three.

Harry himself was too busy zoning out into thin air- pretending that he was listening to Neville's full account of misplacing his treasured remembrall- that he naturally took the ingredient from the other boy, unaware that the item given to him was wrong in the sequence. The Flobberworm mucus was supposed to be next into the cauldron, not the ginger root.

Distracted, Harry scooped a small handful of the ginger, and held it over his cauldron- his attention still on the space Just behind Nevilles left shoulder and not the bubbling potion.

He was just about to drop the ingredient into the cauldron when a hand reach out from nowhere and seized his wrist, snatching his arm away from the potion.

Professor Snape watched through furrowed brows as Potters head snapped up in shock. A gasp tumbled from his mouth, causing all other heads in the room too look over at them.

Severus grimaced down at the two students, dark eyes flickering back and forth between them. Longbottom looked close to wetting himself, barely able to keep eye contact he was shaking so heavily, and Snape grinned inwardly.

Potter however, met his gaze, unflinchingly. Only the small tremor emitting from the arm clutched tightly in the mans grasp gave any indication of the boy's nerves. Snape sneered, because as much as the boy tried hide it, he knew the truth.

He could always see right through the boy.

When he spoke his voice was dangerously low, "drop it".

Harry did so almost instantly- and all eyes watched as the the ginger root slipped from his hand and fell onto the table top with a small 'ping'. The class was silent, the only sound Severus could hear was the Potter boy, as he breathed heavily through his nostrils.

With one last snarl, he released the boy's wrist. Harry snatched his arm back to his side like a whippet, still staring up at him. Neville was looking down at his shoes.

"You idiocy has cost you your potion, Potter" Snape said, voice carrying out across the classroom. With a wave of his wand the cauldron emptied, and the boys' potion was gone. "Clean up your station and see me after class"

As he made his way back to his desk he caught a small snippet of their conversation-

"Did he mean the two of us?" Longbottom asked, "or-?"

"No, Neville" Potter muttered, as he began clearing the ginger root off his work surface. "Just me"

Not twenty minutes later, Severus dismissed his students- all but one, of course- and watched from his desk as the first years quickly filed out of the room- None daring to speak.

Til only Potter was left.

The boy was still stood by his desk area, awkwardly shuffling his feet and nervously clutching the strap of his book bag.

Severus stared up at him for a long moment, drinking him in with calculating eyes.

It was odd to think that the same boy had quite nearly drowned in his arms not a few days earlier. Yet, here he was before him- the picture of health. 'He doesn't know how lucky he is' he thought, jaw clenching.

He stared at the boy for a long moment, before crooking a finger at him, "come here". The child wordlessly obeyed.

He stopped just a few paces short of the desk, close enough to be present in their conversation, yet, far enough to be out of arms reach. He unconsciously rubbed at his wrist, still remembering the long, cold fingers that had gripped him tight.

Severus stared at the boy for what felt a long time, and didn't miss the subtle way his fingers brushed at his arm. He fought a scoff, 'Playing the victim are we, Potter?'

Eventually, he said, "I see you've managed to retrieve your bag?"

"Yes sir" the boy replied, and then with slightly narrowed eyes, "How did you know it was missing?"

Severus grimaced. "Because I, Mr Potter, was 'unfortunate' enough to find it"

Harry fought with everything in him to suppress the grin that itched at the corner of his mouth, he could already hear Ron's reaction in his head when he'd surely tell him later. "You're joking! Professor Snape put his hand down a bog?!"

"Do you know how it might've got there, sir?" He asked instead, voice quiet. 'Did you know one of your slimy Slytherins threw my bag down the loo?' was the hidden message behind his words.

Snapes eyes narrowed, and Harry feared that he'd had sussed out the true intention of his question.
"It's your bag, Mr potter" he said, voice steady despite the irritation he felt bubbling inside him. "you tell me"

"I don't know sir"

"Yes" he said, and Harry swore he could hear the mans teeth grinding against eachother. "You don't seem to know a lot of things lately. Every student with a brain would know that ginger root goes after flobberworm mucus"

Harry felt anger prickle in his stomach, and clenched his fists to his side.

The Professor was being very unfair. There had been no run down of the potion at the start of the lesson, no demonstrations, and no guidance. All they'd had was a list of instructions to follow on the board- and even then, they had disappeared after twenty minutes. How on earth did the professor expect a class of first years to make a potion going off instructions alone?

Harry's mouth opened on instinct, and before he knew it, words came tumbling out-

"Perhaps that isn't always the students fault, Professor"

As quick as it had opened, Harry clamped his mouth shut. He bit down hard on his tongue till he swore he tasted blood, and begged that he'd only imagined he spoke. But it was too late.

The professor was scowling up at him, telling Harry that he had very much heard him.

"Do not give me cheek!" He snapped, leaning forward in his seat. Harry took a step back out of impulse.

"If I needed advice on how to teach my lessons I would ask a qualified adult! Not a simple-minded eleven year old boy who doesn't even know how to tie his own shoelaces yet, let alone teach a room of thirty children!"

Harry frowned, glanced down at his feet, and true to the professors word; found his laces untied. He looked back up to his teacher, who was fixing him with a very stormy look. One that made Harry's stomach do front-flips.

Then, Snape went deathly silent, which scared Harry even more than when he yelled.

Harry averted his eyes, focusing on the spot just behind the mans shoulder, rather than look him in the eyes. Eye contact with Snape was the pinnacle of disturbing.

After a moment, the man spoke, voice incredibly low-

"For your behaviour today in class- not to mention your appalling attitude- you will be serving detention with me on Saturday evening-"

But Harry was no longer listening, for his eyes had glazed over, focusing in and out on the world- and only a few snippets of the professors mantra were able to slip in through the fog in his mind. The rest of it was lost to him as he lazily glanced over the multitude of potions books on the large bookcase behind the desk.

His idle eyes took him to the top shelf, where a few battered old books sat, tucked away out of sight in the far corner, going completely unnoticeable by each student who walked in, including Harry himself. Until now.

Wait. He snapped back to attention, and leaned forward on his tiptoes to see if he had read that properly;

'Meres and mosses: a guide to underwater ingredients'

And the book next to it,

'From Tails to Scales; hidden properties of large-bodied fish'

And the book after that,

'Swimming with the fishes: magical Merfolk mixtures"

"Merfolk" Harry whispered under his breath, his excitement taking the air from his lungs.

"Mr Potter"

Green eyes flitted back to calculating black oynx.

Whoops.

Snape was serving him a very, very mean look.

"Sorry" Harry muttered.

The potions teacher glared at him for another moment or so, before clearing his throat and trying again:

"As I said, You will serve detention with me. Here. Saturday night." He punctuated each sentence as though he were talking to someone who didn't understand a word of English.

"Don't be late"

Harry just nodded, not trusting himself to speak. He bit down hard on the inside of his cheek when he felt a sentence that would no doubt land him in more trouble trying to force its way out his mouth.

Snape gave a curt nod in return, before speaking again, "And the next time you enter my classroom, Mr potter. Be sure to bring your manners, and leave your foolish daydreaming at the door."

Then he was pointing a long finger at the entrance, wordlessly telling Harry to get out.

What Harry didn't see however, as he barrelled out of the door and down the hallway, was a pair of onyx eyes narrow suspiciously after him, before flitting up to the top corner bookshelf.

With a flick of the wrist, the books were magically nudged further back against the shelf;

hidden from sight.

————————————————————————

Later that day, after lessons had finished and all students met at the great hall for their evening meal, Harry excused himself to help Neville look for his- 'remembering thing'.

"Remembrall" Neville corrected.

"Right"

Harry anxiously lead the way down the winding corridors, hoping that his memory hadn't failed him.

It wasn't long before they'd stopped outside a familiar looking room, and Harry's eyes scanned the plaque above. "Lost property".

Bingo.

"Here we are" he said, patting Neville on the shoulder, before steering him towards the door.

Neville instantly had his doubts- much as Harry the other morning. He dug his heels into the floor, halting Harry's movements. "Are you sure were allowed to be here?" He asked, peering curiously over his shoulder to the other boy.

"Of course" Harry reassured with a small smile, before reaching over and testing the handle. The large door gave way with a small 'click'.

"It's not locked?!"

"No need. No one ever comes in here" said Harry, reciting Ron's very same words.

"But we're going in here"

"Huh...you're right" he said, a smile toying at his lips, and a laugh bubbling in his throat, "I guess filch is an idiot, then"

He nudged the Gryffindor forward again. "now, get moving!"

Together, the two boys pushed the heavy entry open, before slipping around the large oak door and into the room.

"Wow" was Neville's reply upon seeing the room.

They immediately set to work, searching. Well, Neville searched, whilst Harry gave a good act at pretending to.

"I'll have a look over there"

He pointed to the far corner of the room, where he knew the old box was waiting.

"Okay" he heard Neville mumble, too busy rooting through a lopsided chest of drawers to hear him properly. Harry watched as the boy nearly ripped the handle off trying to prise the dresser open, before making his- rather dangerous- journey across the room. He tripped at one point, but managed to right himself before he fell face first into a box of broken broomsticks. Ouch.

There he saw the box, exactly where Ron had left it not a week before.

He reached high above his head, grasping the bottom of it, and cautiously tugging the box off the makeshift tower- the unexpected weight almost pulling him to the floor.

Arms straining and legs shaking, a small 'oof' tumbled from his mouth as he took the full weight of the box into his hands.

"You okay?" He heard Neville ask.

"Yeah. All good"

Struggling, he carefully placed the box down before dropping to his knees beside it- embarrassingly out of breath. If Neville were to look over at him now, only the top half of Harry's torso and head would be visable from behind the box.

Without a second thought, Harry dove into action, rummaging deep into the box. Far past the trophies and medals, the swimsuits and goggles- till his hands met the familiar feel of the old photograph.

With a small tug, the photograph pulled free, dust breaking off into the air around him at the movement.

Harry felt a small tickle at his nose, before letting out a little squeak of a sneeze. He heard Neville giggle at him from the other side of the room, saying "bless you".

Harry thanked him distractedly, too busy admiring the photo once more. His eyes scanned the moving image carefully, drinking in every last detail.

The swim team looked back at him. Older, much taller students stood near the back of the photo, whilst the younger students crowded round the front. Two second year girls could be seen linking arms, whilst another pair of fourth years hugged eachother tightly. Several older boys, possibly sixth years, had their arms wrapped over each-other's shoulders, one ruffling his friends hair jokingly. One of the tallest boys even had a small first year on their shoulders- the little boy brandishing a trophy high into the air. Harry smiled affectionately at them.

Everyone was smiling. Everyone was happy.

"Then why would they stop the club?" He wondered aloud.

"What was that?" Neville called, peeking round a long rack of quidditch uniforms.

"Nothin'" Harry said, but Neville was already making his way over to him.

The other boy dropped down next to him with a small "oof", dust immediately clinging to his robes. Gently, Neville took the photo from him.

"I didn't know Hogwarts had a swim team" he said.

"They don't anymore" Harry said, turning back to the box.

Neville eyes narrowed in confusion, "hmm...I wonder why"

Harry nodded in agreement, arms disappearing into the box again.

"Here let me help" the other boy said when he saw him struggling to sift past some of the heavier items. Together they began digging through to the very bottom of the box.

"Hey, these swimsuits have the hogwarts crest on them!" Neville said, "like the quidditch uniform- look, some even have the houses on!"

His words fell on deaf ears. Harry, too distracted too engage in conversation, wordlessly began pulling at a huge pile of aged parchments from the bottom of the box.

"What's that?" Neville asked.

They were newspaper clippings. Most of them, highlighting the awards the swim-team received, some even stating that Hogwarts was the best competing school for swimming in the whole of Europe. 'Wow' Harry thought, goancing back to the photo of the team, 'They must be some good swimmers'. Harry rooted further into the box, fingernails scraping the bottom-side of the cardboard- where he dug up more forgotten articles;

That's where the news took a turn.

Newspaper clippings from the daily prophet, articles taken from witch weekly, and even letters addressed to the headmaster from the minister of magic himself.

"DEATH OF HOGWARTS STUDENT"

"DROWNING IN THE BLACK LAKE: STUDENT BODY RECOVERED AT HOGWARTS SCHOOL OF WITCHCRAFT AND WIZARDRY"

Harry didn't need to look to know Neville was reading over his shoulder, he could hear his breath hitch in horror as he flipped through each headline.

"FATAL DEATH AT HOGWARTS; HOW HEADMASTER DUMBLEDORE FAILED HIS BELOVED SWIM-TEAM"

"This is awful" Neville murmured, breaking the silence that had hung heavily in the air between them since Harry pulled the articles from the box.

Harry found himself nodding in agreement, wanted to stop reading there, but it was almost like he was being compelled to read on. Neville too, from the way he shifted closer, quite nearly breathing down the boys neck.

"Check this, Neville" Harry said, reading a particular passage out loud, "Minister of Magic to prohibit all swimming activities in all wizarding schools across The British isles following the death of hogwarts student"

He skimmed down another article, reading again, "Swimming activities to become illegal commencing the 28th May, 1975"

Neville picked up another discarded Prophet clipping and read it aloud himself, "Any member of staff found to be demonstrating said illegal acts will hereby be released from their position."

Nevilles brow furrowed, and he turned to face Harry. "What does that mean?"

"It means" Harry said, "that if Dumbledore or any other professor decided to start the swim team up again they'd be removed from the school."

"Like, expelled?"

"Yeah" Harry shuffled the parchments in his hands so that they formed a neat pile, "but the teacher kind"

He told Neville to continue looking for his remembrall whilst he tidied up. "Are you sure?" Neville asked. "I can help"

"It's fine" said Harry, as he bagan shoving swimsuits back into the box.

"It's a shame" Neville said after a short pause of searching and tidying on their respective parts, checking through a small standing cupboard full of trinkets, "A swim team would've been fun"

Harry agreed, looking down sadly at a full body swimsuit which looked like it once fit a small first year like him.

"A secret swimteam would've been fun too" Neville continued absently, prying open a particularly stiff cupboard door, dust flying up into his face when it finally gave way and opened. "But a professor wouldn't be able to teach us. And I doubt an older student would risk it either."

Harry blinked, slowly looking up at Neville, swimsuit still in hand.

"They'd get into a lot of trouble with the teachers if they-hey, I found it!" Neville cheered, brandishing his remembrall up for Harry to see. "Thanks Harry!"

Harry didn't speak, he couldn't. His brain was moving ten times fast than the rest of him.

That was it. That was how Harry would learn to swim. He didn't need a Hogwarts teacher or one of the older students to teach him- he knew of a perfectly good swimmer already.

He clutched the costume tighter in excitement;

"A secret swim team"

————————————————————————

"Hello again"

Harry had woken up at the crack of dawn every morning to get his chance at seeing the creature again, and on the third morning in a row he'd finally been successful.

He had just been sitting underneath the Beech tree, throwing a handful of fallen tree-nuts into the shallows of the water and watching them ripple when a familiar pair of black eyes broke the surface- glaring up at him.

"It's Hyrdus, right?"

Harry was feeling particularly brave, considering the creature did not look too happy too see him.

Eventually, the-he? spoke.

"I could have sworn we agreed not to have another repeat of our last meeting, human"

Harry had forgotten how rough the merman's voice was, almost jumping in shock at the harshness of his tone. Nevertheless, he smiled.

"Do you see me in the water?" Harry quipped back good-naturedly, patting the grass on either side of him for emphasis.

Hydrus gave what sounded similarly to a snort. "No, I don't" he said, eyes flickering from left to right to gauge his environment, before allowing more of him to surface. Now his entire head and shoulders were above the water. "That would require you knowing how to swim. And last time you were in the water your pitiful little twig-legs couldn't even hold you up"

The boy looked down at his feet, dejected. He heard Hydrus clear his throat- well, at least that's what it sounded like to his human ears- and change the subject.

"Why have you come back here?" He asked, and not happily either.

"You never said I couldn't" was the smart retort, albeit a mumbled one.

The merman blanched at that- too stunned to form a reply. Possibly because he didn't have one.

The boy looked back up at him, and- visibly pleased that he'd stumped the creature- went on, "You only asked that I didn't tell anyone about you. You never told me I couldn't visit you anymore"

The merman scowled, tail fin protruding from the water to swish about in annoyance. "Well don't." He spat, gills on his neck quivering, "what I did the other day doesn't change anything. you and I are nothing short of strangers. And If you wouldn't mind I'd prefer it if it stayed that way, stick-legs"

If the nicknames were supposed to upset him, then the merman was doing a very poor job.

"Do you know what happened to the swim team here?"

Harry could tell the question took him off guard for a moment, for his tail stopped mid-air, and his all-encompassing black eyes widened significantly.

His voice, though still gravelly and foreign sounding, was quiet when he spoke,

"How do you know about that?"

Harry smiled inwardly in success, happy to have gotten his attention. He fished the photograph and newspaper clipping from his pant pocket- Neville had been unaware that he'd taken a few items from the room in their departure. He'd put them back, eventually. For now, he was simply borrowing them.

He brandished them towards the creature.

"I found this in the schools lost and found" he said, watching the creature draw closer, eyes slitted- reading. When he was finished, he glanced back towards Harry- frowning sharply.

"I'm sure your teachers will not be impressed you went snooping about where you shouldn't"

"I wasn't snooping!" Harry huffed in defence, looking very displeased to be receiving a tongue-lashing from the creature. It wasn't like he got them enough from his professors, now a mermaid was joining in on it?. "I found it by accident"

Well. The First time at least.

Hydrus didn't look convinced.

Harry read the newspaper again.

"It's says a boy drowned here. In the black lake" he looked back up to Hydrus, brows pulled together curiously. "Did you know about that?"

There was a long pause before the merman spoke, words almost imperceptible.

"Yes" he said, "I did"

"The ministry went ballistic about it" Harry went on, "banned all subjects and extracurricular activities involving the sport across the whole country. No Wizarding schools will teach it anymore"

"So I've heard" the creature said, watching the boy carefully. "Where are you going with this?"

Harry leaned forward, voice quieter than before- as though he were telling a secret;

"Can you teach me?"

"What?!" The merman cried, before falling quiet, ducking low into the water as though to hide himself from any other prying eyes- even though it were only himself and the boy present. In fact, he was sure they were the only two awake at this time.

Harry just smiled.

"Teach me to swim" a beat
"Please"

The merman’s neck-gills did that thing again, the shivering motion- reminding Harry of a cat with their hackles raised. He figured it must be something mermaids did when they were angered. “I do hope you're joking" Hydrus said.

“Not at all” Harry said, “That boy could've been me the other day- had you not saved me"

"Well aren't you lucky I did"

Harry had to restrain from rolling his eyes as the sharp retort, and instead settled on a small sigh. Hydrus was making it very obvious that he didn’t favour him in the slightest- for what, he didn’t really know why. He hadn’t done anything wrong. Perhaps it was because he was human? Or maybe mermaids were just bitter by nature.

"But you shouldn't have had to” he pressed on, “I'm eleven. I should know how to swim by now. But I don't"

He elected to ignore the exasperated huff the mermaid gave, pretending to be very interested in the beech nut he rolled rhythmically between his finger and thumb.

"And I'm sick of being afraid of the water” He said, “Sick of being afraid of everything"

There was silence on the creatures part, and after a few beats Harry glanced back up to the shallows- afraid that he’d disappeared below the water. But he was still there, watching him.

"I want to learn to swim" the boy said, firmly. With finality. Like he’d already set his heart on it.

“And what makes you think I'm best suited as your teacher?” The gruff reply. Always harsh, like grinding metal. Harry was beginning to believe that was just the way mermaids spoke. Not at all how he’d imagined them too.

"Because the teachers at the school aren't allowed to help me. They'd get sacked if anyone found out.” Harry said, shrugging his shoulders, before giving him a hopeful look. “Besides” he continued, eyes shining. “You're already in the water"

The merman regarded the boy, eyes flitting down to the newspapers, eyeing them warily. When he spoke, his voice was low again- dangerous. “Put those papers back where you found them, and forget you ever saw me"

Harry gave a cry of indignation, clutching the newspaper parchment tighter. He opened his mouth to protest, but he was beat to it-

"-I can't help you, stick-legs. Forget it"

And that was that.

The creature watched the boy, seeing the way his mouth clamped shut harshly, eyes glossing momentarily, before he blinked away the moisture collecting there. He sucked in a breath, “Okay” he said, sitting back in defeat. “Fine"

The creature gave one short, satisfied nod and watched as the boy climbed to his feet and dusted some stray grass clippings off his robes.

"Well” said the boy, his tone chipper once again- causing the Hydrus’ black eyes to narrow suspiciously. “It was nice talking to you again. But I've gotta dash. I've have a meeting with Professor Dumbledore in his office” The boy picked up his book-bag, and slung it over his shoulder. “Don't want to be late"

Hydrus watched him turn on the spot and begin languidly walking away.

"And, who knows” the boy went on, tone haughty in jest. “I just might let it slip that on my way up I spotted a certain fish-tailed creature" he emphasised, turning his head back to look at Hydrus "lurking about the black lake"

The creatures tail flicked, splashing the water.

"Are you blackmailing me, legs?"

The boy turned, small grin licking at his lips.

"Is it working, fins?"