Symmetry
Jim Moriarty did not intend to date Molly Hooper. Everything he wanted to know about Sherlock, he could have gotten from the friendly work relationship they already had established. He frequently entered her domain, doing repairs, helping her recover files, turn on spell check (he understood—when you need your brain to focus on complex things, the little, generally useless facts get lost—deleted). Many times, she huffed into her office, angry, offended by Sherlock's sharp tongue. Other times, her eyes would be sparkling, her cheeks pink as she chattered about how she assisted the consulting detective in an experiment that uncovered new evidence. Sometimes she just gushed about his cleverness: "He knew just because the ladder was green! How is that even possible, " she laughed.
So, no, he didn't really need to date her. Yet, Sherlock had clearly claimed her as his own. Why? Was it Professional? Romantic? Such a primal instinct! He was surprised to find it in Sherlock. It triggered in him a primal instinct of his own, a need to mark her for himself. It was childish really, the same impulse that made schoolboys grab a mate's cap off his head or steal a packet of cigarettes from the shops, not because they especially want or need to, but just because they can, just because they know it would annoy. St. Augustine and his pears, the long forgotten Catholic schoolboy in him thought—
He watched her through the viewing window as she performed the autopsy of a 45 year old man found murdered in the back of a local bar. Not much of mystery since there were several witnesses who saw who bashed him in the back of the head. No Sherlock needed for this case. Even so, her calm efficiency, eyes lighting up when she discovered an interesting defect in his heart, as she carefully cut a grown man down to his essential parts compelled Moriarty to linger even though the odds of running into the consulting detective were slim.
He was in her small office, ostensibly doing a system update on her computer when she came in after the postmortem, smelling of latex, hospital grade soap, and ever so faintly, something earthy, literally visceral. His eyes were drawn to the rusty drop of blood on her lab coat, dark red against the pure white. She followed his gaze and grinned sheepishly, "They got me!" she gasped clutching her belly, and he gamely pantomimed pulling a trigger. He chuckled thinly before it became a feral smile… somehow Jim from IT was just a bit difficult to channel in the presence of that red droplet.
"What's it like?" he asks, his voice lilting, high pitched. She's scanning files on her desk, looking for a paper that's slipped its binder and doesn't look up.
"What's what like?" she asks absently, still sorting. He stares at the red drop.
"Cutting people open like that?" he asks, letting a bit of wonder creep into his voice. It's not such an act that curiosity, that wonder. He's killed people, oh yes, he has. It's just that he's never really had an opportunity or honestly, the desire, to take them apart afterward, to study what he has done, what he has destroyed. He tended to work from a distance, pulling the strings, staying clean. He often had blood on his hands metaphorically, rarely literally. Yet, here was this petite, good-hearted woman who was often up to her elbows in gore, in the bowels of the dead. Such a bad man with such clean hands. Such a good woman with such dirty hands. A nice sort of symmetry.
She stops flipping through the stacks now, and looks up, her expression guarded. Here was the question again. After the endless coffee breaks and friendly conversations, the question they all asked eventually. The question that usually signaled the beginning of the end.
"I don't know quite how to answer that. Unless you've done it, it's hard to explain," she said as if by rote. She was looking at him, searching his face Why do you want to know the look said. Did he think she think she was weird? Kind of kinky? Was he weird? Was he kinky? The answer was, of course, yes to all those questions, but they really didn't have anything to do with what he was asking.
"Do you like to do it?" he asked looking at her directly, he voice dropping a pitch. With a carefully blank expression, Molly said, "I like my job. I'm very good at what I do."
"But how does it make you feel?" His eyes were black and bottomless as he stared back into her eyes.
She paused, considering those eyes, and in a small voice answered, "Powerful." Silence reigned for a moment as they studied each other.
"And so you are" he spoke softly, understanding in his voice. He smiled again, pointy canines flashing, and moved closer. He reached out one slim finger and touched the red drop. Molly's brow furrowed at this strange intimacy, tilting her head up just in time for him to capture her sweet mouth with his own.