Warnings for Sex and Biting and Really Bloody, Painful Biting at the end (aka 'Marking').

A/N: This story is going to be much darker than either of my previous Vamp!lock one shots, in case you didn't already get that. Marking is not some delicate little nibble on the neck, so consider yourselves warned. But everything leading up to that moment is just pure, smutty goodness, LOL.


Molly was frightened; he could practically taste the fear oozing from her pores as he scraped just the tips of his fangs across her throat, not enough to draw blood but enough to make his intentions clear. Her pulse was throbbing, the blood speeding through her veins, but overriding the fear, even now, was the heady scent of her arousal. If he brushed his fingers across her core, he found himself thinking, would she already be wet for him? His nostrils flared a bit as he scented her, and he smiled as her musk wafted upwards. Oh yes, she would be more than ready for him when the time came to sink his cock deep, deep inside her. She would moan and gasp his name as he sank his fangs into her neck and pressed his fingers into her, then moan even louder when he licked the taste of her sex off his fingers, mixing it with her blood in a cocktail he knew from past experience could be as heady as any Human drug he'd ever sampled.

It was time, he decided, to stop thinking about what he wanted to do to this woman, and to simply...do it.

He'd grasped her arms at some point, although he couldn't say for sure when he'd done so, and pulled her half onto his lap as he dragged his tongue across her throat, pausing where her pulse beat the strongest. "I'm going to bite you, Molly," he murmured against her throat, feeling a shiver go over her body as he spoke. But she wasn't fighting him, wasn't resisting at all; in fact, there was a thrumming eagerness he felt in every muscle, as if she were fighting the urge to do something. But not, he knew, to push him away. "You can touch me, you know," he added, pulling his face up from her neck and allowing her to see his fangs fully extended. The pale light streaming through his window should ensure she could see the whiteness against his lips.

She raised one hand and rested it on his shoulder, the other hovering uncertainly in the air as she hesitated. When she met his eyes and bit her lip nervously, he understood what it was she wanted to do – but was too afraid to ask. He gently reached out and took her wrist in one hand, then brought it closer to his mouth. With his other hand he folded her fingers so that she was making the victory sign, then pressed those two fingers against his fangs, allowing her to touch them as she so obviously wanted to.

A slight intake of breath was the only sound she made as the tips of her fingers made contact with the ivory points, and he watched as her eyes widened and then narrowed in concentration. She leaned forward a bit, as if she'd never seen a pair of fangs up close before – which, most likely, she never had, if the pristine condition of her lovely neck was anything to go by.

It was rare, these days, to see a Human – especially an attractive Human female such as Molly – without so much as a single tiny scar marring their flesh. He wondered if the rest of her body was so untouched, and felt himself hardening further at the thought of being the first to pierce her flesh, to bite her and drink in her blood.

A slight gasp from her lips told him that his eyes had flooded with blood as his arousal increased, coloring the lenses, deepening the natural blue-green of his irises, as he knew from catching sight of his reflection in the past, to a dark purple. Molly pulled her fingers away from his mouth and reached up to tentatively stroke them through his hair, rubbing gently at his scalp and pulling a surprised murmur of approval from him. She grew bolder as he remained passive in her grasp, running her fingers over his shoulders and down his chest. He moaned a bit as her palms scraped over his nipples – they'd always been far too sensitive – and even louder as she allowed her hands to drift to his crotch and the hot bulge of his erection.

At that point he was as incapable of remaining unmoving as he was of existing on anything but blood; he heard her gasp again as he lowered his mouth to hers for a forceful, demanding kiss. The tips of his fangs pierced her tongue as it darted past his lips; the sweet taste of her blood filled his mouth, and all ability to reason, to think clearly, was entirely lost. He pulled himself off her only long enough to shed himself of his clothing, nimble fingers reaching out to undo the front-clasp on her brassiere after she'd tugged her camisole over her head. He tossed both articles of clothing to the floor before once again covering her body with his, groaning at the feel of her taut nipples against the cool flesh of his chest.

Within seconds he'd sunk his fangs into her throat and was greedily sucking down her hot, sweet blood.

VV VV VV VV VV VV VV

When Molly's fingers began exploring Sherlock's lean, muscular frame, she felt her fear sliding from her, and her curiosity about the Vampire who was about to Mark and claim her for his own increasing. Not simply scientific curiosity, either, although she tried at first to tell herself that was all it was; a chance for her to study one of the 'Masters' up close, in an intimate fashion. To explore the differences and similarities there might be between Humans and Vampires, something the pathologist in her was very interested in, although she'd never allowed herself to indulge such an interest in the past.

No, that would be far too dangerous; as soon as anyone, Human or Vampire, discovered that she was researching anything as forbidden as Vampire biology, she would become a person of interest herself, marked by one side as a possible recruit to a dangerous – and ultimately futile – cause, or by the other as a threat to be eliminated.

The irony, of course, was that she'd so carefully avoided giving any appearance of sympathy to either side, yet had landed in her present position in spite of that care. A wry smile curved her lips as she considered her mind's choice of words; her right hand was still pressed against Sherlock's chest while her left had moved downward, coming to rest on the hard bulge of his erection, which – along with his red-flooded eyes – was a very tangible sign that he wasn't simply giving lip service to his brother's demands. What that meant, Molly wasn't entirely sure. Nor was she sure she wanted to know.

Sherlock gave a groan before his lips suddenly claimed hers, stilling her thoughts, and in spite of the jab of pain she felt when his fangs pierced the tip of her tongue as she thoughtlessly plunged it into his mouth, she finally acknowledged that there was nothing scientific about her curiosity at all. This interaction was hardly an experiment, and although the two of them had been coerced into this relationship, it was, indeed, a relationship. One she was going to be entangled in for the remainder of her days.

As Sherlock began shedding his clothing – as she all-too-eagerly joined him – she found herself somewhat troubled by the fact that such a stark reality...did not trouble her. Not at this moment, anyway, when Sherlock's mouth withdrew from hers only long enough for him to dislodge his fangs, and then eagerly lap his tongue against hers, taking in her blood, swallowing it down before he finally moved his mouth to the side of her neck.

A shiver went over her frame, and she could feel her nipples puckering as they rubbed up against the cooler flesh of his smooth, muscular chest. She pictured his mouth suckling the tight nubs, and a groan of want escaped her before she could stop it, her hands moving to clutch at his arms as he pressed a series of open-mouthed kisses along the length of her carotid artery.

When she he drew his head back, eyes blazing with sapphire and gold highlights even through the redness, she had barely enough time to recognize what was happening before he'd darted his head forward and embedded his fangs in her throat.

The pain lasted less than an eyeblink; she'd heard it speculated (but never proven) that Vampire saliva contained some form of topical anesthetic as well as a soporific, an evolutionary advantage to keep prey immobilized after being bitten. The intensely sexual response many had to the bites were rumored to be either the same sort of biochemical interaction (if the Vampire was aroused as well as the victim/donor, it was said to be even more intense) or some kind of psychic ability, similar to the ones many older Vampires eventually manifested.

Either way, Molly could now personally attest to just how fucking incredible it felt to be bitten by a Vampire that was sexually aroused. It was as if his mouth were attached to her cunt instead of her throat; she could feel the growing dampness between her legs, the rising rippling in her abdomen that usually signaled the onset of orgasm, and before she knew it she was gasping and clutching him closer, begging him not to stop as she wreathed her legs around his waist and ground her center against his heated shaft.

VV VV VV VV VV VV VV

Self awareness returned to Sherlock in a rush as soon as he felt Molly's soft, warm body go rigid beneath his. The scent of her sex became overpowering as she orgasmed, her legs clamping around his body, and he pulled his mouth away from her throat in order to gaze down at her in a mixture of smug satisfaction that was purely male (he'd done this to her, turned her into an incoherent mess just by drinking her blood) and amazement that he'd had so powerful an effect on her. Especially considering the fact that he'd deliberately refrained from using any of the usual Vampiric lures on her. No, whatever this was between the two of them – and yes, he reluctantly concluded, it was affecting him as well – had nothing to do with anything as simple or straightforward as pheromones or emotional manipulation or even lust.

Whatever it was, however, would have to be investigated when he had two functioning brain cells to rub together. Preferably after he'd given her another orgasm, this one in the more traditional manner. "Molly, I need to be inside you," he growled, raising his body up just enough to reach down between them and take himself in hand. "I know you're ready for me," he said, pressing the head of his cock against her moisture-slicked entrance. "I know you want me as much as I want you. Say it, Molly," he commanded, not sure why he needed to hear it but knowing that he would only continue if she told him.

"I want you," she whimpered obediently, thrusting her hips upward so that his cock once again rubbed against her wetness. "Please, Sherlock..."

He was inside her as soon as the syllables forming his name left her lips, gliding smoothly, deeply, with no false starts or hesitations. Her internal muscles gripped him tightly, but they were a good fit – a perfect fit, he concluded. As if they were made solely for one another.

He would consider the implications of that – and of everything else that had happened so far this evening – later. Right now he was far too busy turning Molly Hooper into a moaning, writhing mess, waiting until she was crying out with her second climax before once again sinking his fangs into her throat.

Her reaction to his bite was extremely gratifying; even as he continued to piston his hips, driving his prick deep, deep inside her while his mouth worked her throat, she cried out his name, fingernails digging wildly into his scalp as her cresting orgasm seemed to intensify and continue far longer than such usually did.

Now, some deeply primal part of him hissed within his mind, through the haze of his own impending orgasm. Mark her, make her yours.

NOW.

Molly cried out again as Sherlock snarled her name, withdrawing his fangs only to dig them back into her throat, mindless in the mutual throes of passion and bloodlust as his orgasm finally overtook him. This time, however, her cries were of pain, as he ripped at her throat, not content to simply pierce her flesh, overwhelmed by the instincts their fierce coupling had raised within him, instincts he'd never allowed himself to give into ever before. He'd forgotten how raw and primal Marking someone was; the thin veneer of civilization fell away in response to base needs, and the predator within Sherlock exulted at the taste of Molly's flesh between his teeth, the feel of her blood not only in his mouth but dribbling down his chin and smearing itself over their joined torsos.

Her hands had gone from pulling him closer to futilely attempting to tug his head away from her throat, but he ignored her movements as he ignored her cries of pain and pleas for him to stop. He'd warned her, told her he was going to do as Mycroft insisted and Mark her as his own, and right now there was no way he could stop himself even if he tried. His inner predator, the dark, savage part of his nature that he'd worked so hard to suppress, had taken control, and he was powerless to stop it.

Only when Molly fell silent and slumped in his hold did he finally release her, pulling his head up and rubbing his hand across his chin, absently licking the blood from his fingers as he stared down at her unconscious form. He gently settled her down so that her head rested on his now-bloodstained pillow, and he peered down at her throat as reason returned to his mind.

He'd done it. He'd Marked her, made her his. The wound on her neck would take weeks to heal, even if antibiotic creams could be applied. Which, in order to make the Mark permanent, couldn't happen. Although his first thought upon regaining control of his mind was to bandage her, staunch the bleeding, he held off, knowing that it had to bleed long enough for his saliva, with its healing properties, to be cleared from the gash he'd opened on her neck.

He felt sick as he stared down at her, repulsed by what he'd done. Even knowing it was the only way to save her life – that his brother would ruthlessly kill her if Sherlock didn't Mark her in this manner – didn't help, and never would. He wondered how she would feel once she woke up; would she hate him, fear him, be disgusted and horrified by his actions?

He couldn't blame her if she did; after all, he loathed this aspect of his nature, had actively avoided it not only because of the emotional connection Marking could sometimes forge, but also because it symbolized what he saw as the worst aspects of vampirism: violence and the compulsion to bind someone into virtual slavery, to use them against their will, doing physical damage to the body and scarring the mind and heart as well as the body. All things he abhorred and yet here he was, proving himself just as much a slave to his nature as anyone who'd ever been Turned.

The only positives were that Molly would, indeed, be free of the threat Mycroft had levied against her, and that other Vampires would be warned away, knowing that she belonged to a member of a powerful clan. It would no doubt be similar to the Marks Mycroft had left on his slaves – the man had a virtual harem, his brother remembered in disgust. In spite of what he was, Sherlock had always been disdainful of the supernatural, rightly, to his mind, relegating most of it to the realm of superstition, but there were certain aspects of it that could not be ignored.

Such as the way the Mark would bear his initials, in monogram form, once it had finished forming. That was no accident of nature, no logical result of the pattern his fangs had torn into Molly's throat. No, the reddened flesh would bear the white letters "SVH" – Sherlock Vernet Holmes – for the rest of her life.

With a vague feeling of surprise, he realized that he hoped she wouldn't hate him for that same length of time.