John was ashamed to admit that he was surprised when he first saw them. Even after all that time it had been a shock.
It was all Mycroft's fault, naturally. Sherlock had been more than a little unruly and his elder brother had clamped down with hideous efficiency- the silver edged invitations had arrived at 221B Baker St the very next morning on the first post with a barely-veiled threat on the side.
And so John had stood there awkwardly in a hired tuxedo that was a little too big and sipped at a glass of champagne that tasted far too sweet and insipid and leaned awkwardly against a pillar, wishing he were anywhere else, making small talk with people he didn't know and had no inclination to see ever again. He was twisting around to find Sherlock, longing to take advantage of the detective's rudeness and escape home back to a takeaway and some bad television, for the taste of Szechuan pork and egg fried rice instead of tasteless canapés…
And then he saw them- in the middle of the room, oblivious to the other couples on the floor turning to stare at them as they glided serenely across the expanse of marble, the electricity palpable with every move, every perfect step they made together. She was tall and elegant, her eyes flashing with something close to pure danger as she dogged his every step, the red silk of her gown curling and swirling around their legs binding them resolutely. He was luminous in his customary black suit, his slight smile playing with the corner of his mouth and that sociopath's charm, all of his features handsome and sharp, irises silver as he focused, not on her face, but a spot a little below her right ear where a single strand of mahogany hair curled against her neck in a way so enchanting that no formula on earth could decipher it. Whirling faster and faster across the floor, people moving to gape at the act of synchronicity played out, sparks flying and the expression of breathless triumph in the lopsided smile tugging at his lips. There was no love, no mutual affection or trifling inclination but…there. Just there.
Hours later, John found the detective laid out on the sofa in Baker Street, tie loosened around his neck, one single scarlet print on the alabaster skin.