Harry Potter and the Dangerous Liaisons

A Cruel Intentions/Harry Potter cross-over

Disclaimer: I own none of the original characters from either Cruel Intentions or Harry Potter (damn it::bitter:) or most of the books that Sebastian and Kathryn read. However, "The Valentine Trials" and one or two others sprang straight from my imagination.

Eight chapters planned altogether.

A/N: In writing this I ignored the events of the fourth and fifth books. In this alternate Harry Potter reality, Harry, Ron and Hermione faced Voldermort again in their fourth year but everyone escaped alive. Their fifth year was blissfully uneventful. ( :refuses to submit to any scenario in which Sirius dies: )

The First Circle

Students were… swarming… around them. There was no other word for it. Thronging, milling, they all sounded too human by far. They had poured onto the crowded platform like chattering, clamoring insects that buzzed about the ears until one was driven quite to distraction. Once the chauffeur had loaded their bags onto the train, he had left them alone in their carriage to watch in disgust as spotty, pubescent witches and wizards scuttled up and down the corridor outside. The rest of the train was filling up quickly, but no one seemed inclined to try the door to their compartment. In this, the locking charm on the door was almost irrelevant.

Sebastian sighed as he relaxed slightly against the uncomfortably lumpy seat and tilted his head to one side, fixing his step-sister with an inquisitive stare. "Well?"

She rewarded him with tones that dripped sarcasm in the way that a wound drips blood. "Oh, they're delightful. I think I see my new best friend already." She pointed outside to an unfortunate wretch, whose cloak had become fatally entangled in his shoes, causing him to crash to floor amid a mess of limbs and the cacophony of tearing material. The boy, no more than twelve or thirteen, looked up upon feeling identical icy stares fall sharply on him. A shroud of terror passed over his face and he stumbled away like a wounded buffalo under the patient scrutiny of two black-clad tigers.

Kathryn waited for the erratic footsteps to fade before flicking a few tear-away strands of straight, black brown hair over her shoulder and settling herself more comfortably against the rigid arm of the seat. She took a moment to rid her face of its scowl before returning her gaze to Sebastian's face. His frosty blue eyes had not left her. "Never mind, Darling," He commented in his unique, and strangely comforting, drawl. "You've always got me."

Identical smirks flashed over their faces in unison as outside a second year, foolish enough to try the door, found themselves in a heap on the floor with a very bad headache. As though cruelly intending to worsen the poor child's pain a voice crackled through the train. "The food trolley will be proceeding down the train shortly, please have money ready in order to save time. Thank you." The siblings each raised an eyebrow, expressions of perfect condescension rehearsed to precision. After that, their interaction ceased, both conjuring books from their trunks and engrossing themselves therein. When the sweet-lady stopped outside their compartment they waved her on, without looking up from whatever tomes of wisdom had caught their imaginations that day.

Around four hours of dull, grey scenery dragged itself past the windows and, as he light grew dimmer, dusty lamps fluttered into life. The gentle glow sent the passenger's reflections racing to the windows and shadows shrinking back into quiet corners. With her concentration still firmly buried among the pages of "Confessions of an English Opium Eater", Kathryn vaguely thought she heard hushed movements outside the door. Dismissing them as a byproduct of her last fix, she turned the page and tried to keep her attention locked on the printed words. Her eyes narrowed and her head snapped up in annoyance as, with some soft muttering and a mechanical click, the door opened.

A girl's head, framed with curly, dark hair, poked into the compartment. She grinned apologetically as she was met by two ferociously passive stares. There came sounds of a commotion in the corridor behind her and the head disappeared. Sebastian and Kathryn caught a brief discussion as they exchanged looks of uttermost incredulity.

"Just go in. They can't stop you!"

"Hermione, unless You-know-who is sitting in that compartment with two of his favourite death-eaters, all with wands drawn, then there is no earthly reason for us to be standing in this corridor!"

"What if there are three death-eaters?"

"Whose side are you on, Harry?"

"And just what if it were He-who-must-not-be-named? Hmm, Ron?"

"Then Harry should go first!"

"Oh, thanks!"

There were sounds of a scuffle and the girl toppled back into the room, edging over so that the two boys could join her. Sebastian laid down "The Valentine Trials" on the seat beside him and watched the intruders expectantly until one of them spoke. The shorter of the two boys, with scruffy black hair and vividly green eyes, gave him a good-natured smile and cleared his throat.

"D'you mind if we …er, join you? We wouldn't interrupt but our end of the train's fuller than the Great Hall during a dementor attack!"

"Is it?" Sebastian responded dryly, expecting no reply and pleased with the uncomfortable glances he provoked among the new-comers.

"Well, then you'd best join us." Kathryn ignored the sharp look her step-brother shot at her and shifted her bag to the floor so that the others could sit down. The taller boy cautiously seated himself next to her, lowering himself onto the cleared cushion as though half waiting for the chair to swallow him alive – stranger things had happened to him, after all… The other two took the space next to Sebastian who, to as experienced an observer as Kathryn, looked quite ready to blast them all back out of the door.

"I'm sorry we haven't introduced ourselves. I'm Harry Potter." The black- haired boy received grudging smiles for his troubles. "And that's…"

"Hermione Granger." The girl smiled politely.

"And…"

"Ron Weasely." More anxious grins.

Kathryn, with great effort, suppressed the overwhelming urge to throw either them or herself from the train and, instead, fixed her own trademark "the entire world is my friend" expression into place and returned the introductions.

"I'm Kathryn Mertuil. This is my brother, Sebastian Valmont." She waited for them to comment on the names but they didn't. The edgy group was silent for a minute before Hermione spoke up.

"You're new aren't you? I don't remember having seen you around."

"Yes." Replied Sebastian wearily, raising his head from the book he had picked up once again. He resolvedly waved it back into his trunk, resigned to the fact that he would get no further in it on that journey. "We left our school in Manhattan to take our N.E.W.T. s."

"Then you're in the same year as us. Which subjects are you taking?" Hermione's voice held genuine interest, Kathryn realized, almost as though she enjoyed discussing lessons…

Sebastian studied her thoughtfully for a moment, before answering. "Defense against the dark arts, Transfiguration and Potions." Ron made a face.

"Then you'll have Professor Snape!" This seemed self-explanatory; he did not elaborate. Sebastian seemed in no hurry to respond but Kathryn relieved him.

"I'm taking Charms, Herbology, Potions and Arithmancy." In answer to Ron's expression of abject horror, she continued. "Yes, I know four N.E.W.T. s sounds like a lot, but it shouldn't be so very difficult. I did a few extra O.W.L. s and I barely even noticed the difference."

Next to him, Harry felt Hermione's fingers digging viciously into the threadbare cushion. Kathryn noticed a fain twitch start in Hermione's arm, but her hands were hidden from view. The others did not seem in a hurry to volunteer their subject choices and it was not an area into which Sebastian and Kathryn felt the need to pry.

The halting and awkward conversation progressed slightly over the following minutes but Harry and his companions were increasingly unnerved by the strangely aloof Kathryn and her even more puzzling brother.

"So which houses do you reckon you'll be in?" Harry waited without hope for a multi-syllable answer and was surprised to see a flicker of animation in the duo's faces; a tiny spark of amusement flitted between them for an instant.

"Oh, I don't know. We haven't given it much thought, have we, Kathryn?"

"No."

Harry's expectations deflated at so dull a contribution. Still, he persevered. "Perhaps you'll be in Grinffindor with us." He tried, he really did, to appear glad at the prospect. Sebastian made no such effort, sighing deeply and gazing blankly out of the dark window.

Breaking the brittle silence, the voice buzzed around the train again. "We will be arriving at Hogwarts in approximately two minutes. Please leave your luggage on the train, it will be taken to the school separately. Thank you."

So, they were there…