The characters and rights to them belong to BBC and the writers.

A/N: First fic on this website. Criticism is encouraged, but please try to be kind. It's going to be rated M for later chapters, but this chapter is rated T. Please make sure to read the A/Ns before any chapter, there are so many directions that this could go in, so reading about graphic warnings ahead of time might help determine whether or not you would like to continue reading (but I sincerely hope you continue). I'll try to update often if I can, and hopefully I won't stumble into writer's block.

Also, this was non-beta'd, so my apologies in advance for any spelling or grammatical errors. I tried to catch them all myself but there's a good chance some slipped through.

Chapter 1

At the age of 11, Molly noticed that the girl who lived next to her began to act… odd. Only a couple of years older than her, they would walk together every morning to go to school. And yet, on a particularly warm day in May, Melanie seemed to be unusually flustered. By what, Molly had no idea. But she noticed that as they made their way to the school, Melanie was walking in a way that made her legs rub up against each other.

It rather looked like she needed to use the loo.

She overheard later on that Melanie had left for home early, but she didn't understand why some of the older boys were smirking when they said so. On her way home that day, she stopped by Melanie's house to ask after her, but her mother came to the door, quickly informed Molly that Melanie wouldn't be coming to school for the next few days, and then promptly shut it, leaving Molly more confused than she was that morning.

She relayed all this to her dad later in the evening, and watched as her dad turned an interesting shade of pink. After a few moments' pause, he gave out a sigh and began to tell her about Alphas and Omegas.

Melanie was an Omega. But what, exactly, did that mean would happen, Molly wondered. And why were those boys smirking?

And Alfred Hooper, as gently and considerately as he could, told his young daughter that some people in the world respected Omegas, while others treated them rather lowly. That some Alphas see Omegas as people that are used, and go around trying to bed as many as they could. But the best thing an Omega could do would be to bond with someone who truly loved her. And that was very important, did Molly understand? Because one day Molly would have a heat cycle, and she needed to be with someone who wanted to spend the rest of his life with her, not someone who would take her during her time of need and then leave promptly after.

The full implication of being an Omega didn't come to Molly until the following week, when she and Melanie walked to school again. Except this time, there were quite a few boys she recognized that were nearby as well, boys who wouldn't normally be anywhere near their part of town. Melanie noticed too, going by her quickly reddening cheeks, and while she told Molly to ignore them and keep walking, it was rather hard to not hear some of the crude remarks directed at the older girl.

Months later, a day before Melanie missed school again, the comments and whistles that had died down previously started up again, particularly from a few of the older boys. And then Molly decided that being an Omega might just be too much of a hassle. She was already so embarrassed for Melanie, she couldn't imagine how she might react if it ever happened to her.

But it would, wouldn't it? Because according to her dad, it was something that was biological, something you couldn't change, just like how you couldn't change who your parents were.

So Molly, and a rather relieved Alfred, decided to hide the fact that she was an Omega. They bought a particular perfume that would mask her scent as an Omega when the time came, the only thing available at that time. And in any records they had, present or future, they wrote down "Beta" on all of them.

She was still an Omega though, and so preparations were made for when her heat cycle began. Alfred had managed to buy a small place by some woods, the size of a studio apartment and incredibly isolated. Molly would stay there during her heats, and while he would come to check up on her, she would for the most part be alone.

Which suited her just fine. This wasn't something she wanted to share with her dad, no matter how close they were.

In July of the following year, Molly started her heat cycle. It was perhaps the most uncomfortable week she had, with nothing to help her pass the burning she felt. Afterward, she was determined to find some way to ease the discomfort, but first she needed to make sure her secret stayed safe. So she began taking two showers a day and carried the perfume with her everywhere she went. And to her immense relief, no one found out the truth.

SHMH*

Omega suppressant pills were highly regulated, and were only given to Omegas who needed them for a medical condition. Molly, who had successfully identified herself as a Beta, took full advantage of working at a teaching hospital and made her own suppressant. It required some amount of dodging the other staff, but it was amazing what one could do if they bothered to learn a few schedules. It must be how Sherlock always managed to waltz in. Granted, he was allowed to be there, now. But before only she and Mike Stamford knew he even came to the hospital, and that was because Mike was the one who gave him access to the morgue.

It was a strange miracle that she had even managed to keep it from Sherlock.

Speaking of Sherlock…

Dear Lord, but did he weigh a ton. You wouldn't think it, if you saw him. Molly rather thought that he might be thinner that her, and he almost never ate. But here they were, with Molly half holding him up while they walked up the stairs to her flat. She didn't know why Sherlock thought he'd be fine after falling off the roof of St. Bart's, even if he didn't 'fall' like a normal suicidal person.

Molly knew it was a sad state of affairs when one began to think of 'normal' suicidal people and the ways they die.

When they finally made it inside, she kicked her door closed with her foot and then slowly pushed him into her sitting room and unto her couch. Turning on the nearby light, she gave him a closer inspection than she had at the morgue.

All things considered, he really wasn't that bad off. There was still a nasty cut by his temple that needed to be looked at again, and there was definitely something wrong with his leg, but other than that and a few bruises, he was altogether fine. Which was a miracle within itself, really. For one heart-stopping moment, she had actually thought Sherlock had truly died as she stared at him while he laid on her examining table, a needle of adrenaline ready to administer.

And then he coughed, and she almost stabbed him out of fright.

Sherlock leaned back on the couch and closed his eyes, while Molly went off for some supplies to clear his head wound. His eyes remained closed while she bandaged it again, and she would have thought he had fallen asleep if not for his fingers twitching every few seconds. Closer inspection of his leg showed that the muscle had probably been slightly pulled, but no other damage could be seen. After clearing away everything, she came back and sat on the small sitting table directly in front of him.

"Sherlock?"

He opened on eye in response and looked at her.

"I have to go back to the morgue, clear up paperwork and all that. Will you be alright for a few hours? I'll try to run back as soon as I can."

He sighed and closed his eye. "Don't bother, Molly. I won't be here when you return."

"What?"

Sherlock looked at her again. "I'm leaving. There's too much to do, and it has to be done quickly so that I can officially return from the dead. The longer I linger, the more opportunities are missed." He sat up on the couch. "Thank you, again."

Sherlock looked as if he wanted to say more but was rather holding himself back.

Molly slowly got up. "Er… you're welcome." She looked around the room a bit, trying to think of something to say. What did you tell someone who wasn't dead, but you're the only person who knows he's alive? "If you could –"

The words died in her throat, because when she had turned her eyes to Sherlock again, it was to see Sherlock staring at her with the most peculiar expression. Molly thought it looked like he was trying to deduce something from her, but it wasn't only that. There was something else, and if Molly didn't know better she would have thought it was… lust.

Which was patently ridiculous. Sherlock was asexual, everyone knew that. Or in some weird arrangement with John, despite the blogger denying it so avidly. Last she checked, John was a Beta while Sherlock was an Alpha, so who knew what went on between them behind the door of 221B.

Whatever that look was, it became even more intense as Sherlock replied, "Yes?" in that deep voice of his. It was a shame that it did nothing for Molly anymore. Once, a while ago, Sherlock was all Molly could think about, but a girl could only take so much and not be disenchanted with him. She hadn't even stuttered in front of him for the past 5 hours.

"What? Oh, erm… right, I just wanted to ask if you could, that is to say, if you have time, and you aren't too busy –"

"Molly."

Damn. Now she was rambling. Which was not her fault. If only he would stop looking at her like that, she'd be fine.

"Right, sorry. I just – I'd like to know you're still alive. When you're out – wherever, I guess. A text or a phone call or an email…" She trailed off with a nervous giggle.

That look finally disappeared, to be replaced with his normal countenance. "Not safe. Anyone could track me by a phone or could potentially get to you. You're the only one that hasn't been threatened, Molly, let's try to keep it that way, hmm?"

Molly looked disheartened. "Oh. Right." She looked around her flat again. "Well, do try to be safe," she said awkwardly.

Sherlock turned around and fully laid down on her couch, hands steepled under his chin. He grunted at her, and then closed his eyes and became as still as a statue.

Molly stared at him for a moment longer, then went to pick up her coat and keys before heading to the door. Just as she was about to open it, she heard Sherlock call her name.

"Yes?"

There was another pause, and then, "Thank you. Really."

Her lips broke into a small smile, and she looked at the back of the couch fondly. "You're welcome. And stay safe." With that she left for the morgue.

Sherlock stayed still for about 3 minutes before his eyes snapped open again. He got up and did a cursory scan of the sitting room and what he could see of the kitchen, reaffirming what he knew about Molly Hooper.

Except, for some reason, the entire place smelled faintly of Omega pheromones. The scent had been even more potent fabric of the couch, which was strange, because Molly was the only that had sat there for the past few months.

Sherlock looked around the room again, then towards the couch, and then at the door that he determined led to her bedroom. He smirked.

Well. There was always the one thing, wasn't there?