DISCLAIMER: I am not JKR. Everything that you recognise in this story belongs to her not me.

Written for Taragh McCarthy's 1st annual Halloween Competition on HPFC

Pairing: Lucius/Narcissa

Costume: She Devil

Prompt: Fire Cracker

"I can't believe I'm doing this."

Narcissa stared at her reflection in the mirror, wincing at the length of the stiff red skirt, or rather the lack of it. Her mother would be scandalized! Of course her mother (and father and most of the oh so Noble and Ancient House of Black) seemed to lose all sense of fun and impropriety once they hit twenty.

Helen MacMillan giggled as she affixed a pair of dainty horns on Narcissa's head.

"All done," she pronounced, stepping back carefully, so as to not tangle her cutlass in the lace of Narcissa's corset.

When Marty Prince and Christina Selwyn had decided to throw a Slytherin Halloween party after the feast, the four sixth year girls had agreed to let the other three come up with each of their costumes, using only their own abilities in transfiguration and charms. Helen had ended up as a pirate, her golden curls bundled up in a bandanna, with an eye-patch, and a red lacy cloak. Narcissa had even swallowed her pride and talked Sirius into showing her how to transfigure a stick into a sword. He'd though the whole thing an excellent idea and was petitioning the Gryffindor seventh years to throw a party too.

Tessie Parkinson was done up as a medusa, her head-dress made from a collection of transfigured stockings knotted together and charmed to move. She hadn't quite worked out the implied insult yet, much to the other girls' amusement. Morganna Downes was dressed as a muggle nurse, including a white skirt shorter than the one Narcissa herself was wearing, and a ridiculous red bow in her hair. She had taken the jab at her ancestry (her grandmother had actually been a muggle nurse, serving at the front in World War one, where she had met her wizard husband) in good humour as she always did.

Narcissa suspected Helen was behind her outfit. Tessie didn't have the brains or the subtlety, and Morganna had developed a half-blood Slytherin's instinct of not provoking pure-bloods, especially those of old and powerful families. A she-devil. Succubus, temptress. An underhand jibe about the events of last summer that Narcissa was definitely not going to think about. No, tonight was going to be about having fun, dancing with her betrothed, Lucius, and avoiding Perry at all costs.

Besides, she had had nothing to do with her sister's elopement. While it was well known that Drommie and Lucius had been at best civil to one another despite their betrothal, Lucius clearly preferring Narcissa's company, there was absolutely no truth to the horrendous rumour that Drommie had left because Lucius and Narcissa had...no she was NOT thinking about that. Drommie had run off with her pet Mudblood because he had gotten her pregnant, and she had refused to get rid of the abomination.

"Are you coming Narcissa?"

Morganna was holding the door, while Tessie offered her a black and red trident.

Fun and dancing, Narcissa reminded herself as they headed down the hall to the common room. Fun and dancing.

The party had already started by the time they got there. A cauldron full of smoking green punch rested on the table, Lucius and Christina, the head boy and female 7th year prefect fastidiously looking away while Martell added a few extra highly dubious ingredients. He grinned at the girls over an empty bottle of Newtscotch, showing off his fake vampire fangs.

Lucius came to her with a smile, dressed as the Norse god Baldur. He did look like the pictures from some of their Ancient Runes texts, with his flowing silver hair and strong grey eyes. He kissed her hand and offered her a glass of punch, collected prior to any alcoholic introductions, he assured her.

In the corner Tristan Weyland and Peregrine Harper were arguing with the wireless, eventually prevailing as the music started. Perry was dressed in Arrows robes, his second best broom at his side. He had been the champion Slytherin seeker since his second year, and had trained last summer with the Appleby reserves. Neither he nor Narcissa had been particularly upset about their engagement being broken. While he had grown from an awkward, gangly, pimply youth into a tall, fresh-faced athlete, his only passion was Quidditch. His parents were new money, who had been looking for a way in to old pure-blood society, and had arranged the betrothal to the youngest Black daughter through Aunt Walburga and Uncle Orion. He and Lucius had never gotten along, and she was glad to not be stuck in the middle of that argument any more.

Her musings were interrupted by Lucius plucking the empty glass from her hand and twirling her into a dance. She laughed as they waltzed around the tables, moving smoothly and precisely, much better than any of the other clumsy couples. Morganna and Helen had grabbed Tris and Perry, and some of the younger students had shyly joined in.

Several songs later, Narcissa laughingly begged for a break, and collapsed into a chair as Lucius went for drinks. She noticed that Christina had drawn an age-line around the alcoholic punch much to the dismay of several of the fourth year boys. The party was in full swing now. Marty had returned from a pilfering raid from the kitchens with several trays of pastries, in case anyone hadn't eaten their fill at the feast. Arista Montague was shoring up the silencing charms on the door, letting Travis Gibbon from Narcissa's year feed her a Danish. Tessie was sitting in Tristan's lap, while Helen danced with Perry. A pack of first years, including her cousin Regulus had started a boisterous game of exploding snap in the corner, laughing as the sparks set their paper hats on fire.

Dancing and Fun. And Lucius.

He was on his way back with a pair of glasses when the room exploded with crimson and gold sparkles. The fireworks, apparently slipped inside the door during Martell's return, spiralled and crackled, culminating in a roaring lion's head just above the punch. It didn't take a genius to work out the culprit, though Narcissa suspected Sirius and his little second-year friends would be half way back to their dorm by now.

She quickly adopted an outraged expression as Lucius tried to bat out the sparks in his hair while juggling two goblets of punch. Clearly he had no doubt as to the culprit either. But tonight wasn't about stupid cousins or past promises. Tonight was about fun and dancing and enjoying the last of her youth, before the adult world sapped it away. So she smiled as she brushed the ashes from his hair and took the glass from his hand and tickled him with her trident. And they danced some more.