disclaimer: mine, actually. well, moira, her family and all future oc's belong to me. harry potter belongs to the wonderful j.k.r
dedication: to…i dunno, whoever wants to have it dedicated to them
notes: so, here is my first take on a harry potter story: yes, with an oc, but she isn't a mary-sue…i hope….

title: by trial of fire
summary: its moira o'shea's fourth year at hogwarts, and with the rising threat of voldemort, the triwizard tournament and her strange dreams, this year's bound to be a doozy. Harry/OC

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prologue

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'Hey, can I sit here? There's no room anywhere else.'

Harry and Ron looked up from their seats at the doorway, where a young girl around their age stood, her trunk and owl-cage just visible beyond the edge of the door. She had her arms crossed over her chest and a medium sized, rather fluffy gray, brown and black owl perched on her shoulder. The owl hooted cheerfully and blinked wide, shiny black eyes at the two boys.

Ron recovered first. 'Ah, sure, go ahead.'

While Harry cleared off a space for her to sit, the girl occupied herself with hauling her trunk into the compartment and, with Ron's help, shoved it into the luggage rack. After thanking Ron for his help, the girl flopped back into the seat and smiled. 'So, my fellow compartment mates, I believe introductions are in order.'

Ron and Harry looked at each other; Harry ended up speaking for the both of them. 'I'm Harry Potter, and this is Ron Weasley.'

'Nice to meet you,' she said in a pleasant Scottish accent, not even fazed by Harry's name. 'I'm Moira O'Shea – you can call me Mo- and this,' she guestured to the fluffy owl on her shoulder, 'Is Jareth. Ooh, can I have a chocolate frog?'

'Jareth?' said Ron as she attacked the sweets pile and dug out two cauldron cakes and several chocolate frogs. 'What kind of a name is that for an owl?'

'Well,' said Mo through a mouthful of cauldron cake, 'I named him after a character in my favourite movie – my favourite character too, coincidentally. He looked so much like the owl form of the character that I couldn't resist.'

Ron looked confused, so Harry spoke. 'What movie?'

'The Labyrinth.' She replied, inspecting her chocolate frog card as the candy tried to hop to freedom. 'You know, with David Bowie?'

Her jaw dropped at Harry and Ron's confounded looks. 'Dance Magic Dance? The Goblin King? You have no power over me?' Her horror seemed to grow as their looks of confusion deepened. 'Oh lord; I've stumbled onto a bunch of pure-bloods haven't I?'

'Well, I'm a pure-blood,' said Ron, 'but Harry was raised by Muggles. I really don't see how our blood status is important, though.'

'And you haven't seen the Labyrinth?' she demanded. When Harry shook his head, she moaned pathetically and tossed a chocolate frog at his head. 'For shame, Harry, for shame; I can't believe you, a wizard raised by Muggles, haven't seen that amazing movie!'

Poor Ron just looked painfully bemused now. 'What's so important about this movie?' he asked.

'It is only the best thing ever invented since Star Wars!' she cried enthusiastically. 'That's it, this summer, both of you are coming over to my house and we are watching the Labyrinth, yeah?'

'But, we just met you,' Ron protested. 'How do you know we'll still be friends at the end of the year?'

She blinked at him. 'Well, won't we?'

'Well, yes, I guess…' Ron muttered, and Mo beamed.

'There you have it then. This summer, both of you, my house and the best movie ever made. Deal?'

She stuck her hands out and Harry and Ron, grinning, each took one hand and shook it firmly. Leaning back in her seat, Mo smiled.

'I think this is the start of a beautiful friendship, mates.'

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The station was crowded with kids ranging from eleven to possibly eighteen, all dressed in black robes and all talking very, very loudly. Harry and Ron pushed there way through the throng towards Hagrid, who was shouting for the first years over the babble of the crowd.

The giant grinned upon spotting Harry, his black eyes crinkling. 'All right there Harry?'

'I'm fine Hagrid,' said Harry.

Hagrid's hairy face beamed at him over the crowd.

'C'mon, follow me – any more firs' years? Firs' years, follow me! Mind yer step now!'

Slipping and sliding everywhere, they followed the groundskeeper down what appeared to be a very steep, narrow path. It was extremely dark on either side, and Harry figured they were walking through a patch of forest. None of them spoke much, which probably explained why Harry and Ron jumped a foot in the air when Mo appeared at Harry's elbow; Jareth still perched on her shoulder.

'This is so cool!' she whispered, nearly vibrating from excitement; Harry agreed whole-heartedly.

'Yeh'll get yer firs' sight o' Hogwarts in a sec,' Hagrid called over his shoulder, the lantern swinging in his hand, 'jus' round this bend here.'

They rounded the corner; a loud 'Ooooh' echoed from the first years as the path opened up on the edge of a big, black lake. Perched atop the cliffs on the opposite shore was the biggest castle Harry had ever seen, with many towers and turrets reaching into the sky.

Hagrid pointed to a fleet of boats bobbing on the shore. 'No more'n four to a boat!' he called.

Harry, Ron and Mo were followed into their boat by Hermione, a girl they had met on the train. Neville, the boy who'd lost his toad, was in a boat with a sandy-haired boy, a girl with her blonde hair in two braids and an African-American boy.

Hagrid settled himself in the lead boat, which sunk dangerously low in the water. 'Everyone in? Right then – FORWARD!'

At his command, the little fleet of boats began moving smoothly over the lake, which appeared to be as smooth as glass. No one spoke as they approached the castle, not even Mo, whose eyes were almost as wide as her owl Jareth's. Harry's jaw fell as they came closer and closer to the castle, which towered overhead. It was even bigger than he had first thought.

'Head down!' yelled Hagrid as they approached reached the cliff; they all bent their heads as the boats carried them through a tunnel in the cliff-face, which was hidden by some ivy. Harry figured they were travelling straight under the castle, which eventually opened up into some kind of underground harbour, where they all scrambled out onto the rocks and pebbles.

'Oi, you there! Is this your toad?' Hagrid asked as he turned from inspecting the boats. A toad was grasped in one large hand, and Neville's boyish face beamed.

'Trevor!' the boy said blissfully, taking the toad from Hagrid.

They then clambered up a passage in the rocks after Hagrid's lamp, finally emerging onto the wet, smooth grass of the grounds, right in the shadow of the castle. Walking up a flight of stone steps, they gathered around Hagrid as he looked over their heads.

'Everyone here? You there, you still got yer toad?'

After making sure everyone was accounted for, Hagrid raised a gigantic fist and knocked on the door three times.

Immediately, the door swung open, revealing a stern-looking witch with black hair pulled tightly into a bun and emerald green robes. Harry and Mo shared a look. 'She's not someone I want to cross,' Mo whispered.

'The firs' years, Professor McGonagall,' said Hagrid.

'Thank you, Hagrid,' said McGonagall, her voice heavy with a Scottish brogue. 'I'll take them from here.'

'Oh my god, she's Scottish!' Mo squealed in Harry's ear. 'Like me! Wicked!'

The doors opened wide, revealing an entrance hall so big it could have fit four of the Dursley's houses, easily. The ceiling was too high to make out, with a set of huge marble steps leading to the upper floors.

Harry heard the drone of voices from a door on his right as McGonagall led the first years to a small chamber off the hall. They all crowded together, looking about nervously. Mo was grinning like an idiot, looking at everything at once.

'Welcome to Hogwarts,' McGonagall started briskly. 'The start-of-term feast will begin shortly, but before you can take your seats, you must be sorted into your house. There are four houses at Hogwarts: they are Gryffindor, Hufflepuff, Ravenclaw and Slytherin. Each house has its own noble history and has produced outstanding witches and wizards.'

She fixed her stern gaze on each of them. 'While you are here, your house will be like your family. You will eat with your house, attend classes with your house and, if you choose to, spend your free time in your house common room. Any triumphs will earn you points, while rule-breaking will cause you to lose points. At the end of the year, the house with the most points will be awarded the house cup, a prestigious honour.'

'The sorting ceremony will take place in a few moments in front of the school. I suggest you smarten yourselves up while you're waiting.'

Her eyes travelled from Ron's smudged nose to Neville's cloak, which was clasped under his ear. Harry nervously tried to flatten his hair, while Mo sent Jareth off to wherever the owls go and brushed feathers off her robes.

'How do you suppose they sort us?' Harry asked.

'Dunno, some sort of test I think. Fred said it hurt a lot, but I think he was joking,' said Ron.

Harry swallowed. Moira laughed. 'We're first years Ron, and some of us are Muggleborn,' she pointed out. 'I doubt they'll make us do anything bad, or hurt us. Besides, from what I remember, I think we just try on a hat.'

Ron looked relieved, and opened his mouth to speak when several people screamed, causing him, Harry and Mo to jump about a foot in the air. Behind them, about twenty pearly white figures were floating through the walls, completely ignoring the first years. They seemed to be arguing about something; a fat little monk was saying, 'Forgive and forget, I say. We ought to give him a second chance –'

'My dear Friar, haven't we given Peeves enough chances? He's not really a ghost, you know, and he gives us all a bad – I say, what are you all doing here?'

A ghost wearing a ruff pulled high on his neck and tights suddenly noticed them. No one answered him, but the Friar smiled at them all. 'New students! I hope I see some of you in Hufflepuff; my old house you know.'

At that moment, McGonagall chose to return. 'Move along,' she said sharply, watching as each ghost floated through the wall and out of sight. 'The ceremony is about to begin,' she told them, 'Form a single line and follow me.'

They all filed into line; Harry ended up behind Mo, with Ron behind him. They quietly followed McGonagall out of the room and through a huge set of double doors into the hall. Harry's first thought was that the hall was beautiful. A thousand floating candles illuminated the starry sky, and although Harry heard Hermione whispering how it was simply bewitched to look like the sky outside, it was really hard to believe the hall just didn't open to the heavens.

Hundreds of faces looked at them from four long tables, and Harry fought the urge to squirm nervously. They gathered at the front of the hall, in front of a long table where the teachers sat. McGonagall had placed a rickety wooden stool in front of the first years. On top of the stool, she placed an old, frayed hat.

The entire hall stared at the hat, waiting. After a moment, its brim opened wide and it began to sing a tale about the four founders of Hogwarts and the tale that brought them to this. As it finished its song, the entire hall burst into applause, falling silent again as McGonagall unfurled a scroll.

'When I call your name,' she said, her voice ringing around the hall, 'You will come forth. I will place the sorting hat on your head, and you will be sorted into your houses.'

She looked at her scroll. 'Abbott, Hannah!'

The girl with blonde braids stumbled out of line and sat on the stool; the hat fell right over her eyes. There was a moment's pause –

'HUFFLEPUFF!' yelled the hat.

The table on the far right cheered and clapped as Hannah went over and sat down. Harry saw the Fat Friar wave merrily at her.

'Bones, Susan.'

'HUFFLEPUFF!' the hat yelled again, and Susan scurried off to sit next to Hannah.

'Boot, Terry!'

'RAVENCLAW!'

This time, the table second from the left clapped; several of them shook Terry's hand as he sat down.

'Brocklehurst, Mandy' went to Ravenclaw too, while 'Brown, Lavender' became the first Gryffindor, causing the table on the far left to explode into cheers. Fred and George, Ron's twin brothers, were catcalling.

'Bulstrode, Millicent' became a Slytherin, and sat at the last remaining table, second from the right. It might have been Harry's imagination, but he thought they looked like an unpleasant lot.

He glanced over at Mo, who was once again shining with excitement. She glanced at Harry and flashed him a smile. Her happiness was infectious, and he felt some of his anxiety leave as he turned back to the sorting.

'Finch-Fletchley, Justin!'

'HUFFLEPUFF!'

Sometimes, Harry noticed, the hat shouted out the name at once, while others, like 'Finnigan, Seamus', who was on the stool for a full minute before the hat declared him a Gryffindor, took longer.

'Granger, Hermione!'

Hermione practically ran to the stool and jammed the hat on her head. It only took a few moments for the hat to yell, 'GRYFFINDOR!'

Ron groaned, making Mo elbow him sharply in the side. He winced, rubbing the sore spot and glaring at her. 'I don't want to be in the same house as her!' he whispered fiercely. Mo just glared at him and told him to shut up.

Neville was up next. He sat on the stool for a little until it declared him a Gryffindor. He was so eager to go sit down that he forgot to take off the hat and, amongst gales of laughter, ran back to hand it to 'MacDougal, Morag'.

'Malfoy, Draco!'

Malfoy swaggered up to the stool arrogantly, and Harry grinned as Mo booed softly from beside him, her eyes narrowed. The hat had barely touched his head before it shouted, 'SLYTHERIN!'

Malfoy sauntered off to sit with Crabbe and Goyle and Mo sighed in relief. 'At least you and I know we won't get into his house,' she murmured.

The numbers slowly dwindled down. There were two more M's…then a 'Moon' … 'Nott' … and finally –

'O'Shea, Moira!'

Mo practically bounced to the stool, flashing a grin at Harry as the hat fell over her eyes. It was dark inside the hat, and she nearly jumped as a voice whispered in her ear.

'Oh yes, what a fine mind you have. Plenty of courage, loyalty … such a thirst for knowledge, much like your mother …'

'My mother?' Mo replied tentatively. 'My mother's a Muggle. Irish, and completely brilliant, but Muggle.'

'Not that mother, your real mother, oh, she was just like you, a fiery Scots girl in the middle of proper Britain,' the hat said softly. 'Oh, ambitious are we? But you wouldn't do well in Slytherin, too hot-headed for them. You would do well in Hufflepuff; Ravenclaw too. Your intelligence rivals that of your mother, but your loyalty…that is your father in you. However, I don't think they quite suit you; you are fair, but your stubbornness tends to get in the way of judgement, and you seem to like to leap before you look… ah, just like your father I see; you'll do great things, Miss O'Shea, just like him. Good luck in – GRYFFINDOR!'

The last part was shouted into the hall and Mo blinked as spots dotted her vision after so long in complete darkness. Heading over to the table, she slid into a seat next to Seamus and flashed Harry and Ron thumbs up.

There were hardly any left now. 'Parkinson' … 'Patil' and 'Patil' … 'Perks, Sally-Anne' … and then finally –

'Potter, Harry!'

Whispers broke out at his name as Harry stepped forwards nervously. Turning, his last vision was of hundreds of eyes staring up at him before the hat fell over his eyes. For a moment, all was silent, and Harry started to panic. What if he wasn't sorted? Would they send him home?

A voice in his ear nearly made him jump off the stool. 'Hmm…' said the voice, 'Difficult, very difficult. Plenty of courage I see, not a bad mind either. There's talent, oh yes, and such a thirst to prove yourself… very interesting. So where shall I put you.'

'Not Slytherin!' he thought with all his might, and he heard the hat chuckle.

'Not Slytherin, eh? Oh, you could be great you know; Slytherin will help you on your way to greatness, no doubt. Well, I do suppose you would do great things no matter what house I put you in … well if you're sure, it'd better be – GRYFFINDOR!'

The gold and red table burst into applause and Harry let a grin spread across his face as McGonagall removed the hat and allowed him to head towards his new housemates. Several people shook his hand as he headed for Moira and sat down on her other side. He could dimly hear the Weasley Twins shouting, 'We got Potter! We got Potter!'

'Nice one Harry,' she whispered as the clapping died down. 'I knew you'd be a Gryffindor.'

'You didn't even know what Gryffindor was until ten minutes ago.' He replied, amused.

She huffed. 'Well, whatever. Oh look, Ron is getting sorted!'

Harry turned and had to stifle a laugh. Poor Ron looked rather green around the gills as he sat on the stool and the hat was placed on his head. Harry and Mo crossed their fingers, and a second later the hat shouted, 'GRYFFINDOR!'

Ron practically threw the hat off his head and slumped in a seat next to Harry, ignoring his brother Percy's pompous, 'Well done, Ron.'

The last boy, 'Zabini, Blaise' was sorted into Slytherin. McGonagall took away the stool and hat as Albus Dumbledore got to his feet, smiling at them and opening his arms wide, as if to sweep them all into a hug.

'Welcome, welcome, to another year at Hogwarts!' he said. 'Before we start the feast, I would like to say a few words. They are: Nitwit! Blubber! Oddment! Tweak!'

'Thank you!' he sat down and Harry looked at Mo in surprise.

'Is he mad?' he asked tentatively.

'Mad?' said Percy airily. 'He's a genius! But, I suppose all geniuses are a bit mad. Potatoes, Harry?'

Harry's jaw dropped as he looked at the gleaming gold dishes, previously empty, and now piled high with food. Mo had a similar look of astonishment on her, while Ron was simply piling a little of everything onto his plate. Mo and Harry quickly followed his example and tucked in.

A thought struck Harry and he swallowed a forkful of mashed potatoes before turning to Mo, who was pouring gravy on her roast beef. 'Wait a – Mo, aren't you a Muggle-born?'

'Yeah. What of it?'

'Well,' said Harry slowly, 'If you're a Muggle-born, how did you know what a chocolate frog was? Or how we'd get sorted? I thought only people who grew up in the magical world knew those things.'

She chewed thoughtfully at a piece of roast beef for a moment before answering. 'When I got my letter, my parents, naturally, didn't believe that magic existed. So, the school sent Professor Sprout over to my house to explain it all to my parents and take me shopping.'

A dreamy expression crossed her face as she smiled wickedly. 'You should have seen their faces when Professor Sprout levitated them, the couch and the lamps two feet off the ground. I thought they were going to have a heart-attack! Anyways, after that, Professor Sprout took me shopping and explained some things about the wizarding world. She explained the four houses to me, and explained the sorting too, when I asked about it. She also gave me the book Hogwarts: a History to read. It explained everything else. Good book, really.'

Ron, who'd been listening onto their conversation, spoke around a spoon of peas. 'How'd you buy all your things? Do they have a trust fund for Muggle-born students or something?'

Mo frowned. 'I dunno. Professor Sprout just said my schooling had been taken care of, but I don't think my parents know any witches or wizards.'

Shrugging, she dug into her food again, and was soon smiling and joking with Seamus and Dean, the African-American boy she had met on the train, before she stumbled on Harry and Ron. Throughout the whole meal, she couldn't shake the words the sorting hat had whispered in her ears.

'…like your father … like your father … great things like him … a thirst for knowledge like your mother …a fiery Scots girl stuck in proper Britain…'

She had thought her accent had come from living in Scotland until she was seven, and her stubbornness and unwillingness to give up the accent when she travelled with her parents.

If her parents weren't Jack and Melissa O'Shea, Irish and two of the top biologists in the world, then…who were?

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notes: well, there's the prologue. i just wanted to introduce mo's character here, and the sort of mystery around her birth and up-bringing. i might go back and write books one and two and three later, but right now i want to focus on the fourth book. it's my favourite after all. *wink* and please review…she doesn't seem like a mary-sue, right? i did the mary-sue litmus test and she came out with a six, which is the thesis of an anti-sue according to the results, but i want to know what you think.

so, enjoy!

edited: 30/07/12