willardhewitts answered you: Awesome :D The prompt I had in mind could work with any rating, so that's fine. I have no preference for K+ vs. T. Anyways, the prompt: After I watched TEH, I had the idea that Tom wasn't actually Molly's fiancé; he was her bodyguard. Mycroft had him start working with Molly after The Fall and purposefully chose someone who bore a resemblance to Sherlock so it would be easier to accept that Molly was in a relationship with him. (Tom's a bit skinny to be a bodyguard, but we'll say he's trained in martial arts that rely more on agility than brute strength, I guess.) Only Sherlock doesn't know that Molly isn't legitimately engaged to Tom, and he gets jealous. Molly assumes Sherlock does know the truth about Tom, and she gets confused. It ends with Sherlock finding out the truth and make-up making-out at her flat or something.

A/N: This is a complete AU starting with "The Empty Hearse" and ending with "The Sign of Three", because the fact that Tom is a fake fiancé would come to light during the Hallway Conversation between Molly and Sherlock after she spends the day solving cases with him. Enjoy!

Molly was engaged. How could he have missed it before? When he'd shown himself to her in the locker room at St. Bart's, where she'd just been preparing to start her overnight shift, she'd not had a ring on her finger, true, but he still should have noticed. But no, he'd been too busy drinking in the sight of her lovely face after two long years of not seeing her anywhere except in his Mind Palace and the occasional embarrassing dream. Too busy cataloging the joy in her expression, the way her lips moved when she smiled and how nicely her hairstyle framed her features to take in the appearance of her hands. The slight indentation on her left ring finger, the paleness of the skin – yes, Molly's skin was naturally pale, but there was still enough of a difference for his normally-acute eyes to take in.

Engaged. To be married. To a man. Someone else…well, of course 'someone else' since it wasn't him.

Oh, wait. Did that mean he would prefer Molly Hooper were engaged to himself? Sherlock pondered the question for the next several days, then decided the only way to determine if that was the answer (naturally enough) was to perform an experiment. John still wasn't talking to him (although Mary kept him regularly and clandestinely up-to-date on his angry best friend), Lestrade was pestering him to take up cases again, his in-box was full…asking Molly to help him, to spend the day working on cases, would serve multiple purposes, he decided. First and foremost, it would allow him to determine if his unhappy reaction to her engagement was this emotion "jealousy" he'd heard thrown around so often but had no recollection of ever having experienced for himself.

oOo

Two days later, experiment complete…Consulting Detective disgruntled. He was, indeed, jealous of the fact that Molly Hooper was engaged to be married to another man. Specifically, to a dull clod like Tom whatever-his-last-name-was (Sherlock had deleted it within seconds of hearing it) instead of to someone more deserving of such a wonderful woman. Someone, he concluded, like himself.

No, not just LIKE himself – she deserved to be engaged to Sherlock Holmes. Even if he didn't deserve to be engaged to her, since he was bound to muck things up if he ever did enter into a relationship with her. She'd kick him to the curb quickly enough for forgetting anniversaries or not taking her to dinner or running off on an out-of-the-country case and not letting her know. And he'd deserve it, which is why it was for the best that it wasn't Sherlock Holmes to whom Molly Hooper had become engaged.

He'd tried to pretend it didn't matter, but the day Molly spent helping him with cases proved only that she'd gotten under his skin to the point that he couldn't ignore the truth. He didn't just trust her; she didn't just count, she mattered more than anyone else in his life, including John. So when he almost impulsively asked her if she wanted to have chips at the end of the day, it was for the best that he'd bit back the words.

So he told himself, over and over, after saying good-bye to her that day. The fiancé had shown up as they left the building and Sherlock had choked out a greeting and a smile that even the dimmest of dimwits would see was false and gone back to 221B and smoked an entire pack of cigarettes. Molly was engaged, she belonged to someone else and Sherlock Holmes would just have to get used to it.

No matter how much the thought of her and that buffoon having sex clenched his gut. Especially after Molly went out of her way to tell him they were, the day he asked her for help calculating the perfect alcoholic intake for John's stag night. "We're having quite a lot of sex," he muttered to himself, a savage mimicry, as he waited for John to put in an appearance at Baker Street. "Hah! As if I care! What difference does it make if she and Mr. Pathetic Wishes-he-could-pull-off-the-dark-coat-and-scarf-look-as-well-as-I-do are having 'quite a lot of sex' or no sex or occasional sex? None, that's how much! Absolutely none!"

"Sherlock? Who are you talking to?"

He started at the sound of his name, but managed to pin a bright smile on his face as he spun around and saw John leaning against the doorframe. "Myself, the skull…take your pick, John!" he said airily. "Ready to go, are you?" He clapped his hands together. "Great, fantastic, let's do this!"

John gave him an odd look, then shrugged and followed as Sherlock swept past him out the door.

Of course the stag night didn't go as planned; Sherlock wanted to blame Molly for getting the calculations wrong, but John's confession that he'd spiked the drinks with shots a few times solved that mystery. "Of course Molly didn't get the calculations wrong," Sherlock muttered to himself as he prepared for the wedding. "Molly doesn't make mistakes like that."

Thinking about Molly made the preparations go much faster, and before he knew it, he was done. Dressed and ready to act as John's best man, a role he'd never ever expected to fulfill. Still, he felt he acquitted himself fairly well, even with an attempted murder thrown into the mix…and even with his awareness of Molly Hooper throughout the entire ordeal.

Molly, with her cheerful yellow dress and matching pumps and the bow-thing in her hair (he later learned it was called a 'fascinator' which was fascinating all on its own)…and the positively idiotic fiancé hanging off her arm. "Meat dagger," Sherlock muttered to himself when he'd returned home that evening, letting loose a sardonic bark of laughter as he lifted his violin to his shoulder. "Hah!"

How Molly could possibly have gotten herself engaged to such a complete and utter moron? Because he looked a bit like the man she really loved – or rather, used to really love? Could it be that simple? His eyes brightened at the thought, then darkened as he shook his head at his own idiocy. The Molly Hooper he'd left behind almost three years ago might have kept her feelings to herself (he ignored the jeering voice in his head that no, actually, she hadn't done that at all), but the Molly Hooper he'd returned to was much more confident and self-assertive. If she still loved him, she'd let him know.

Like tonight, for example. Even though it appeared she'd been jealous of the attention he'd paid to Janine, he'd obviously misread her emotions. Otherwise she'd have followed him when he left the wedding early, stopped him, told him he was being a berk or begged him to come back…

He was so lost in his fantasies (wait, when had thinking about Molly become fantasizing about her?) that it took him a moment to realize he was hearing voices and footsteps on the stairs. He lowered his violin and stared at the door, eyebrows climbing as he recognized the voices.

Molly and Tom. Here, at his flat. Why? They couldn't possibly have a case for him, could they? Or – horrors! – they hadn't decided to impulsively elope and needed him for some reason? To act as a witness or get Mycroft to open up a registrar's office for them?

He moved closer to the door, as the couple outside seemed to have stopped and were…arguing? He grinned, then snapped his mouth downward in annoyance. He didn't need to hear John telling him 'not good' to know that it wasn't nice to revel in someone else's misery, but it sounded like Molly was upset with Tom, who was whispering furiously to her about…what was he saying? Something about not leaving her alone, or someone would have his head…

"Oh for God's sake!" Sherlock snarled as he yanked the door open, startling the furiously whispering pair. They stood just at the top of the stairs as he glared at them, focusing his attention on Tom and for the first time really looking at the man. Deducing him, which he'd avoided doing for Molly's sake. "Whose idea was it? Mycroft, I presume?"

Tom and Molly exchanged puzzled glances before looking back at the enraged detective. "Uh, yeah, I report to your brother," Tom replied guardedly.

Sherlock snorted. 'Guardedly' was exactly the right word to use. He turned his ire on Molly. "And you opted not to inform me that your 'fiancé' was actually your bodyguard…why?"

Molly's brow wrinkled in confusion, and Sherlock felt the rare sensation of realizing he'd been wrong about something as she replied, "Wait, are you saying…that you didn't know? You didn't deduce it?"

Her delighted smile at having caught him out only served to darken his scowl as he tried frantically to backpedal. He hated being shown up by anyone, even Molly. Well, 'hated' was probably too strong a word, but he intensely disliked it. "Don't be ridiculous, Molly," he snapped. "Of course I knew. I just didn't know, uh, if he'd been assigned to you by my brother or by Graham."

Molly looked confused, so he clarified, since she probably didn't know the DI's first name. "Lestrade."

"Greg," she corrected him, and he blinked. Oh, right, Greg, he knew that. Unimportant, just like the man standing next to Molly on the stairs.

"Leave," he barked out imperiously. "Molly is safe with me, you know that or you wouldn't have left her side for an entire day when she worked with me."

The thin man's entire demeanor changed, from awkwardly hunching body and slightly vacant expression to ramrod straight posture (hands dangling by his sides but now Sherlock noted them as the weapons they actually were, some sort of martial arts training to make up for the slender physique) and the hardened stare of a complete professional. "I have my orders," Tom – or whatever his real name was – began, but Sherlock cut him off.

"Yes, your orders. On my brother's behalf, as we've already established." His eyes narrowed and he raked the bodyguard from head to foot and back again, lips stretching in a knowing grin. "Do go and wake him up, won't you? Tell him you're ready to move back into his bed again. I'm sure he missed you, but I do appreciate him sending his best man to guard my pathologist. However, I'm back now and perfectly able to take on the job myself." He sniffed. "In fact, I'm not sure why you did stay on so long."

Tom mumbled something about Sherlock needing to focus on getting his own life back together before being entrusted with anyone else's, but the consulting detective had dismissed the man from his mind, focusing instead on the one person who truly mattered. The one who'd remained silent during the entire exchange between the two men.

The one he wanted desperately to kiss, but refused to do so until they were alone. "Good night, Tom," Sherlock said pointedly as he reached out and offered Molly his hand. As if she were some delicate flower who couldn't manage the last two steps on her own, but he didn't care how it looked, only that the gesture was made.

"It's Dave, actually," the fake fiancé muttered, but Sherlock barely heard him as Molly reached out and placed her (much smaller) hand in his, smiling sweetly up at him. He heard her murmuring something that sounded like thanks to the bodyguard, but ignored that as well, focusing intently on the lips shaping the words and not the words themselves.

Those words were supremely unimportant to him; the only ones that mattered were the ones that confirmed that Molly Hooper was not actually engaged to be married. With that in mind, he plucked the ring from her finger and held it up to her. "You can return this to your jewelry box, Molly. Your aunt would no doubt have been pleased that her ring once again saw the light of day, but the one I plan to purchase for you will fit your personality much better."

Molly was gaping at him, and he mentally reviewed what he'd just said to see why she appeared so shocked…then flushed a bright red as he realized how much he'd given away in his joy at discovering she was still available in a romantic sense. "I, uh, that is," he mumbled, but Molly hushed him with a quick peck on the cheek before she turned back to Tom…Dave, rather. His befuddled mind recalled that much.

"Give our love to Mycroft, Dave, and tell him thanks for lending you out but Sherlock's right; he can take it from here," Molly said firmly, and finally the infernal man was leaving and Molly was practically dragging Sherlock back into his flat and when the door was shut behind them, she was pulling his face down for a lingering kiss that left them both breathless when it ended.

"So," Molly murmured when she could speak again, staring dreamily up at Sherlock. "About this ring you plan to buy me…"

"A square-cut sapphire, with either smaller white sapphires or diamonds on either side, in a white-gold setting," he replied without needing to think about it. Because of course he'd subconsciously known exactly what sort of ring he would buy for Molly Hooper if he ever needed to do so.

Like now. He bent down to kiss her again, but she pulled back and smirked at his confused expression. "Telling me what sort of ring you plan to buy for me is all well and good Sherlock," she said with a giggle, "but if this is meant to be a proposal, aren't you forgetting the most important part?" When he simply gave her a blank look in response, she prompted gently, "Maybe you should actually ask me first?"

His face immediately formed itself into a scowl. "I am not getting down on one knee like some idiotic romantic-comedy leading man," he said firmly. "Certainly not when I don't even have the ring in my possession to present to you." His expression softened, and he reached up to brush a few loose hairs that had escaped from Molly's up-do away from her face. "However, I would very much like to ask you if you would do me the honor of becoming my wife, Molly Hooper, in spite of the fact that I don't deserve you, and won't be at all surprised if you tell me no…"

Soft lips met his, cutting off his words before he could go into the long list of reasons why Molly shouldn't marry him. He closed his eyes and drew her closer, enjoying the way she fit so snugly against his long, lanky form, not minding in the least how he had to bend his head in order to reach her. It occurred to him that even if he did mind, the solution was a simple one; she squeaked a bit as he pulled her up into his arms and carried her over to the sofa, easing her onto his lap without actually breaking the kiss. Her arms had moved automatically to settle on his shoulders, and he felt her fingers running through his hair, a sensation he thoroughly approved.

"In case you were wondering, that was a yes," Molly murmured against his lips when the kiss ended.

He lifted her now-ringless left hand and pressed a kiss to the slightly lighter band of skin where her aunt's ring had once rested. "Yes, I thought as much," he replied, skimming the tips of his fingers lightly over the area, already picturing her hand with his ring on it instead. A real engagement instead of a false one set up to protect her from any enemies that might have decided to target her in his absence. If only he hadn't been so busy trying to let her go, he would have realized sooner that 'Tom' wasn't who he appeared to be.

He smirked. On the other hand, he'd effectively kept Mycroft and his own personal 'goldfish' apart for longer than his brother had bargained for, which was a bonus. That would teach his older brother to let him be tortured in Serbia.

Then he kissed Molly again, pushing Mycroft and what's-his-name firmly out of his mind. He and his newly minted fiancée had a lot of catching up to do.