The Sweetest Sin

Disclaimer: I don't own 'Harry Potter' or 'Percy Jackson'. All recognisable characters, content or locations belong to their respective owners. No copyright infringement intended.

Summary: A daughter of Aphrodite, a son of Apollo, and a world of possibilities. Gwen Potter has enemies though, and Michael Yew's not exactly threat free either, but all's fair in love and war, and sometimes, the risk is the best part. "Is that a harmonica in your pocket, or are you just pleased to see me?" AU. Fem!Harry. Gwen/Michael

Rating: M for language, violence, mild adult themes, character death, and teenaged debauchery.

Author: tlyxor1.

Prologue

Despite herself, and all the children she'd birthed in the past, it never got easier. And this one, this perfect, flawless angel, would be beautiful, and wondrous, and it broke her heart.

Such a gift, with her father's sable hair, and her own flawless complexion, would come with a price, and already, the strings of destiny had been tethered around the babe's tiny heart. Her life would be hard, perhaps more so than Aphrodite herself could predict, but the laws were laws, and to defy Zeus, her King, would see the babe dead.

She wouldn't let that happen.

Not when this girl, with her plump, rosy lips, and thick, sable lashes, was perhaps her favourite daughter of them all.

And so she settled the infant in a woven basket, with a hand stitched blanket wrapped around her, and walked away. Behind her, as James Potter woke, Guinevere Potter slept on.

And Aphrodite wept.

Chapter One

The hound was enormous, far larger than Fluffy, with eyes that burned like an inferno, and sharp, proportionately massive fangs. It blocked her path to the street, she was exhausted, and so she found herself at a stalemate, or perhaps a crossroad, with one question to answer: should she fight, or flee?

Raised and trained by heroes, and inspired by them too, Gwen Potter had never run from trouble.

This time would be no exception.

With an indrawn breath, Gwen palmed the handles of her daggers, braced her weight, and watched, gaze narrowed, as the hound shifted it's own mass, ready, and waiting.

For a brief, fleeting moment, she wished for a celestial bronze equivalent of throwing knives, but then the hound lunged at her, and Gwen didn't much have the time for idle thoughts. She threw her focus into the fight instead, her muscles burned, her heart thundered, and yet, she came out of the brief skirmish as the victor, with a hellhound fang for spoils, a slash to her forearm for her trouble, and an exhaustion she could feel in her bones.

"Are you alright, Mr Tumnas?" She asked, and her satyr companion appeared from beneath Gwen's invisibility cloak, a disgruntled frown on his face.

"You need to stop calling me that."

"It's a term of endearment," she answered flippantly, "Let's go."

They stepped out onto the street, headed for the underground, and boarded the first train to Manhattan. She'd never been to New York in her life, but she'd lived in London long enough, and the foreign sites, though interesting in that tourist sort of way, didn't hold her attention the same way it would for anyone else.

She was not here to site see, after all.

"I killed someone when I was eleven," she admitted, and her keeper, whose name was actually Morris, tilted his head, curious, but not accusatory. "He was possessed by Voldemort, and he was trying to kill me."

"That was self-defence," Morris answered, "It's not your fault - just like the hellhound."

Gwen huffed a hollow laugh, turned her gaze to the window, and wished she could believe him. That knowledge, however, had gnawed at her for years, and it wasn't going to go away so easily. So many others had said the same thing - her family, her friends, the faculty - and yet, the memory of Quirrel's skin bubbling beneath her hands, the echo of his tortured screams, the acrid stench of burning flesh, lingered in her subconscious, and she was certain it would never fade.

At New York's City central station, the pair transferred onto the Long Island Rail, Gwen withdrew a rubix cube from her bag, and occupied herself with the puzzle until they reached their stop.

It had been a gift from Remus, who always got Gwen little gifts that challenged her, and it was probably the only thing that had kept her sane since she'd left London.

That had been three days ago, and they'd been travelling ever since - plane, then foot, and most recently, train - and the witch, and recently discovered demigod, thought she'd never missed London more in her life.

She'd not even been so homesick her first week at Hogwarts.

"Are you excited about camp?" Morris queried.

Gwen twisted her lips, furrowed her brow, and considered the question. She'd been trained since she was young in Tae Kwon Do, Karate and Judo, and when she was twelve, she'd taken up lessons to learn how to properly use her blades.

In essence, she didn't feel she needed to learn an entirely new fighting style, but another part of her, young and optimistic, was excited to meet others like her - demigods - and she couldn't deny herself if she tried.

"I'm excited to get away from the monsters," she answered, "And to sleep in a real bed."

"I'm afraid the camp's bunk beds will be a far cry from the opulence you're familiar with," Morris said.

Gwen arched an unimpressed eyebrow, and her expression was deadpan. "Do you think I give a damn about that?"

Unconventional in her attire, she'd opted for a pair of purple skinny leg jeans, the biker boots her godfather had gifted her, and a pale grey 'Rolling Stones' band tee. Her hair was long though, pulled into a solitary French braid down her back, and in essence, she looked nothing like the pureblood heiress she was supposed to be.

"Touche," Morris conceded, "But in my defence, you looked like a princess when you opened the door."

Gwen scoffed and shoved her new friend, but a blush stained her cheeks, and a smile pulled at her lips. "You're just an A-class silver tongue, aren't you, Mr Tumnas?"

He sketched a mock bow, his hat wavered on his head, and he replied, "That's me, smooth talker extraordinaire."

The rest of their train ride was spent in idle conversation, and the pair exited the train in Long Island, with yet another leg of their journey ahead of them. She grimaced at the thought, felt for the bronze rings on her index fingers, and walked beside Morris as he led the way through the station, headed for the exit.

"Brace yourself," Morris warned her, headed to the taxi bay, "The last leg is the worst."

"That's comforting," she deadpanned, followed him into the backseat, and turned her attention to the scenery passing them by. "You just made my day, mate. Seriously."

Sloping hills, blue skies, and the occasional glimpse of the bay, the pair rode in the company of a cantankerous foreigner and the sound of Avril Lavigne through the speakers, but Morris stopped them beside a strawberry field, with a hill far out in the distance, and surrounded by forestry.

She wondered briefly if they were going to start snitching strawberries, but before she could raise the question, Morris guided her towards the trees, and she swore violently.

"Are you fucking joking?"

"I'm afraid not," Morris answered, "Come on, I smell monsters."

"That's bloody nice, isn't it?" She groused, but followed the satyr all the same, braced for anything.

"I don't think you understand," Morris was saying, "Your scent is crazy powerful - like one of the big three - and it's kind of unbelievable to think that you're actually a daughter of Aphrodite, traits notwithstanding. Never mind that though, you're like a siren call to anything - men, women, monsters - and not just because you smell good."

Uninterested in the conversation, she tuned his tangent out, and instead focused on their surroundings, on the silence of the trees, of the tension in the air, and she inhaled deeply, certain that she was currently being hunted. She didn't know what was stalking her, but the sensation of prey, meet predator was not a pleasant one.

Morris, who'd fallen silent, met Gwen's hazel eyes, with his own brown gaze, wide and fearful. "There's so many."

She shivered.

"You have to run," Morris implored, "I'll hold them off."

He withdrew his panflute, but he trembled violently, and Gwen set her expression, determined. She was scared though - terrified, even - but she would never leave a friend behind.

"I won't leave you."

"Please," he entreated, "I couldn't live with myself if you got hurt again. You just need to top the hill. Past the pine up there, and you'll be safe."

Gwen looked around her, and licked her lips, her mouth dry. They were almost fully circled by all manner of monsters, and the only way she could make it to Camp Halfblood alive was if an intervention was had.

And yet, Morris was her friend.

Conflicted and frightened, she met Morris' gaze again, and his smile, though tremulous, was genuine. He put her cloak in her hands, folded her fingers over the material, and squeezed them briefly. "I'll meet you on the other side."

Gwen nodded, and ran.

As the haunting melody of Morris' panflute whispered through the trees, she didn't look back.