The week went quickly, and John came home from surgery to find Sherlock in his room. He had two suitcases: a small, rolling grey case, and a larger black one. The grey one had already been packed, and was situated near the wall. The black one was open on Sherlock's bed as he packed. John watched the spectacle in front of him with interest: it was different, this time. Usually, Sherlock was a dervish of hands and shirts, stuffing the closest things to him into the case. But now, he was slow, considering: He picked out the thickest socks he owned, even though it wasn't expected to be particularly cold; his hands moved to the back of his underwear drawer, drawing out a handful of silk boxer shorts and soft cotton pairs without fly buttons; he stroked each article of clothing, considering, before he packed it neatly into his case.

Given that he was going to the Holmes' manor, he was surprised when Sherlock took out at least a dozen t-shirts, and added them to his case. He pulled out three pairs of pajama pants, which was unusual as well; he'd been introduced to the fact that Sherlock slept naked when he'd ended up at the Palace in just a sheet. He walked to the closet, running his hand thoughtfully along silk shirts before pulling them out, and then he did the same for the black slacks hung up next to them. With a flourish, he pulled not one, but two dressing gowns off hangers as he made his way back to the bed. It was at this time that he noticed John.

John recovered quickly: "Just wanted to ask what sort of take-away you wanted for dinner." He hoped he sounded casual, and not at all like he'd been watching Sherlock pack for the last five minutes.

"Chinese. The good place – run my card. I'm sure I'll be subjected to 'traditional British fare' while I'm away," he replied, the scorn evident in his voice. As John walked away, he heard Sherlock swear under his breath… Yes, Sherlock had been very odd these last few weeks.

John sat in the living room, glancing at his watch occasionally to chart the progress of the Chinese food. They had said it would be an hour. Might as well catch up on his latest medical journal before Sherlock managed to set it on fire.

" 'Fecundity's Holy Grail: The Male Omega'," Sherlock read, over John's shoulder. He flopped down on the couch, and asked, "The Chinese is sorted, I take it?"

"Yep. I can leave to pick it up in twenty minutes. Have you read this one? It's quite interesting."

"I skimmed it. What I got out of it is most of that lot is sterile."

"That's true. But the ones that are fertile are extremely so. Although oral contraception is mostly prescribed for off-label usage, like mood management and reduction in heat symptoms."

"Hmm," Sherlock agreed noncommittally.

"The most popular ones decrease cramping and crying spells, among other things."

"You're just reading it off now, aren't you?"

"No, that's just my experience as a doctor. Although for every young male omega I see, I get three confused young betas. It seems sexual education has fallen to shit this past year."

"I shudder to think how ignorant I'd be if I had been forced to learn this sort of thing from my family."

Sherlock didn't elaborate, and John knew this was as far as he could push it without shutting Sherlock down entirely. He waited a few minutes then put the magazine facedown, open on the article. He laced his trainers and went to get the Chinese…

As the two relaxed in the living room, chopsticks digging into Lo Mein and Szechuan pork, Sherlock asked, "Aren't you going to pack, John?"

"Tomorrow," he answered, rooting around in his container for water chestnuts.

"Right … You're leaving the day after me."

"Mmm," he agreed, mouth full of food.

Later that night, Sherlock lay in bed, very much awake. He tried to sleep, knowing in two days he'd get none, when he was alerted to the sound of John's pacing footsteps above him. John hadn't done the pacing bit in awhile, and Sherlock, realizing sleep was a waste, quickly made his way upstairs. If John was up, he figured they could go over cold cases together.

As he neared John's room, he heard John bark out in a hushed tone: "What do you mean I can't stay there? Harry, this is important!"

He listened for a minute and then replied, "'Not safe'? We've had this worked out for months. Christ, I – yes, Sherlock will be gone. That's not the point!"

He listened for a moment more, then sighed: "Goodnight, Harry."

Sherlock knew a sibling squabble when he heard one. He quickly walked downstairs, and decided to tackle his cold cases alone.

The next day, Sherlock wheeled his black suitcase into the living room, while John sat curled on the couch, typing on his laptop. "Ah, the 'red-headed league'?" he asked, as John typed quickly.

"Hmm? Yes, just putting the finishing touches before I pack."

"Pack? You're going to pack?" Sherlock asked slowly, uncertainly.

"Yes, I've put it off long enough," he replied, eyes glued to the computer screen.

"You know John, if anything should happen, and Harry needs a place, she can stay while I'm away. You can take my bed, since I won't be needing it." He had hoped broaching it this way would get John to confess what had happened with their row.

"Oh, um, thank you, Sherlock. I'll be sure to pass it on." With that he closed the laptop, and tucked it under his arm. A horn honked outside, and Sherlock started. John held out a hand, and Sherlock shook it.

"See you in a week," he said, and John nodded. He waited until the town car was out of sight before he flipped his laptop back open. He'd been looking for cheap motels nearby, specifically those that catered to rut/heat needs. He was having trouble finding anything secure enough for his price range. He sighed, and typed a new phrase into the search engine: "pick up/drop off laundry service", and typed the number into his phone.

"Yes, hello? I wanted to inquire about prices for a pick up/drop off service to Baker street?" He paused to listen.

"Yes, and I have a few more questions: is there anything you don't treat? I see – no, nothing like that."

He could feel a blush creeping onto his face as he asked, "And all your delivery workers… are they-" He took a breath, before relief washed over his features. "Betas? All of them? You sure? Excellent."

"Thank you, that's all for now. I'll be ringing soon, then."

He clicked the phone shut, and was on his way to the kitchen to make himself a cuppa when a sudden pain punched low in his gut. 'No,' he thought, his heart racing, 'this isn't supposed to happen until tomorrow…'

With shaking hands, he hit redial: "Yes, hello, I just spoke with you? I'd like a pick up/ drop off at the end of this week to 221B Baker Street." He gave his credit card information, and hung up, breathing shakily. He pulled a cloth bag out of the pantry and went upstairs as quickly as he could.

Not safe, not safe, NOT SAFE.

He scented the air: Mrs. Hudson downstairs – beta; Mr. Robinson upstairs – beta; Ms. Fenton next door – omega. In fact, the closest alpha was out on the street below, a policeman.

Logically, he knew he was safe. But the other part of him, the more primal part, didn't feel it. He closed the door behind him, locking it tight and quickly went through his closet, pulling out provisions: the cloth bag contained food and water, since he doubted he'd get much chance to leave his room; he yanked out his softest terry cloth robe, although he knew he wouldn't be able to stand even that after the first day; he pulled out slippers, noise-cancelling headphones, a dehumidifier, a fan, extra blankets, and every towel he owned.

He began rifling through his drawer, checking his prescriptions and assuring himself he'd taken what he needed to. He pulled out a large bottle of paracetamol, along with an eye mask, a box of gloves, and a thermometer. He moved all of these to the night stand and unmade his bed, knowing he'd be holed up here for a week.

Across town, Sherlock sat in the back of the town-car uncomfortably. He pulled at his collar, suddenly too hot. He looked down at his shaking hands, shifting to accommodate his slowly-growing erection, the fabric of his suddenly-uncomfortable slacks straining.

"Stop the car. I need in the boot."

The driver stopped and Sherlock bolted out, making his way to the popped door. He stared in horror at the boot's contents: a single black suitcase. He'd forgotten the grey one.

STUPID! How could he be so daft?!

He closed it quickly and got back in. "Turn around. I've forgotten something very important at 221B."

Back at the flat, having arranged his room properly – windows blacked out, appliances set up, bed arranged - John stood in the shower, trying to get clean as quickly as possible. He'd had a shower just that morning, but considering the way his brain was fogging up, he knew the other physical signs would come soon. Best to get a shower in while he could still manage standing.

Once he was out, he shaved quickly, and was reaching for his aftershave when he remembered: the aftershave that was usually so agreeable to him was an absolute assault on his senses when he was off his suppressants. He shook his head and brushed his teeth, feeling the prickle of a fever beginning under his skin. At that moment, he wished he was a beta; only alphas and omegas had to deal with the feverish delirium of their hormones. He spit into the sink, and quickly made his way upstairs, towel tucked tight around his hips. He managed to make it to his room, and locked the door before he felt it: he was sweating in strange places, whereas everywhere else was bone-dry; his scalp and the back of his neck began to sweat, and he could feel himself begin to get hard. As he tossed the towel aside, he caught a glimpse of himself in the mirror on the closet door: his cheeks were slowly reddening, and he had a flush from his neck down to his belly-button. He tore his eyes away, and got under the covers, taking as many of the pills as he safely could to curb his worsening fever. His senses were becoming keener by the minute, but his brain was sluggish, working at half-speed.

"Drive. Faster," Sherlock snarled, unable to contain his irritation any longer.

"Sir, we're still 20 minutes from Baker Street. Should we get pulled over, I doubt you'd be able to make it the rest of the way in your … condition." The driver pushed a button and the partition came up, as Sherlock spewed abuse at him.

What had made it worse was that the driver was right: Sherlock was sweating, close to fever, and soon he'd feel the tell-tale pheromone sweat on his neck. He unbuttoned a couple of buttons on his silk shirt, his skin radiating heat, and turned the air conditioner up. As long as he could get to the case soon, he didn't care if he ended up "soiling" the backseat in a hormone-fueled sex haze.

His hands were shaky as he typed out a text:

If at home, please place grey suitcase by door. – SH

He waited anxiously for John's reply, but it never came.

John could hear his phone buzzing from his desk – it was so loud. But by this point, his legs didn't seem to want to work. Sherlock had said he'd be unreachable, so he pushed the thought from his mind. If he could just try to sleep, he'd be saved from this misery for an hour or so.

He knew his efforts were in vain: the only thing that brought on sleep when he was like this was sexual exhaustion; and even with John's best efforts, without fulfilling his urges properly, he was looking forward to a lot of sleepless nights. Despite this, he might as well give it a go: he took his cock in his hand and stroked, but the feeling wasn't enough. Luckily, John was more prepared this time than the last; with his free hand, he opened the drawer to his nightstand, and reached inside.

The town car stopped in front of 221B abruptly, and Sherlock bolted from his seat. He scrambled with the keys, ignoring the concerned look from Mrs. Hudson as he rushed towards the stairwell. He took the stairs two at a time, ignoring the ache in his groin from his insistent erection. Dropping his keys, he cursed and picked them up, hands still shaking. It was setting in much more quickly than anticipated. He opened the door, and as he pushed in, an unfamiliar scent assaulted his nose. He looked around, trying to assess the situation as he walked up to his room, but he felt himself getting slow. Just as he crossed the threshold and spied the case, he placed it: natural scents – seawater and juniper – underlay a spicy scent, something even Sherlock wouldn't have been able to detect, were he not in his current condition. There was unmistakably the scent of John, too: earl grey and wool jumpers flooded his senses, almost as an afterthought.

John must have company.

Sherlock knew it was dangerous to stay here in this state, but his curiosity got the best of him as he took the stairs, case forgotten. It wasn't until he got to John's door that the full reality of the situation set in: he was smelling an omega, in heat.

His hands shook and his mouth watered at the prospect, as he forced himself down the stairs. He had to get out of here, fast. He grabbed the case and was almost to the door when he heard it – or rather, didn't hear it: John moaned loudly, unable to control himself. But there were no other moans, no pants. If John had an omega in there, in heat no less, he or she wouldn't have been able to keep quiet for the life of them.

John was alone.

Sherlock dialed quickly: "Go back. I'm staying here."

He clicked the phone shut, and took the stairs again. The close proximity to an omega had renewed his vigor and he grabbed at the door handle, frustrated to find it locked. He took a deep breath, the scent making the hairs on the back of his neck stand on end.

"John," Sherlock intoned, his voice coming out between a growl and a purr. When John failed to respond, he banged on the door. "John, are you all right?"

His protective instincts came to the forefront of his mind. John was hurt. An omega was hurt.

It took him a few tries, but Sherlock kicked the door in. The room was dark, and it took a few moments for his eyes to adjust. In this time, John scrambled into a sitting position, heart racing. He ripped the obviously too-effective headphones off of his head, and curled the blankets tight around him, although by this point he was sweating bullets.

Sherlock's keener ears perked up in response to the sound of a clatter against the floor; his eyes roamed, making out the sex toy that had fallen out from John's covers: it was a large toy with a flared base and a knot-mimic, and looked slippery. He looked back at John, whose expression was quickly morphing from mortified to enraged.

Sherlock's nostrils flared, taking in the strong scent of the omega before him. Although John's usual tea/jumper scent was often unobtrusive it now radiated off him, the natural omega scent mingling underneath it. As his wide pupils took in the altered scenery of John's room, John seemed to find his voice:

"Sherlock?! BLOODY HELL! Get. Out." His voice came out hoarse, a combination of raspy pants and low threats.

"You're an omega." Sherlock accused, as he stepped closer. Normally, he'd heed John's warning, not wanting to be on the bad side of that temper. Now, however, he couldn't help but find it intriguing.

"Oh, sod off you damn – oh." John sniffed the air experimentally, not sure he could trust his senses. He smelled Sherlock – starched silk and loose tobacco – but the scent below that… It was unlike any alpha he'd ever smelled: he smelled like dark roast coffee and no, it couldn't be. Sugar? John had heard omegas were supposed to smell sweet, but never an alpha. John's skin was practically buzzing, his fingertips yearning to touch the man before him. His hole throbbed, slick leaking from it down into the sheets below.

"You're not a beta."

"No … of course not. Why would you think that?" Sherlock still advanced slowly. All of his previous knowledge of the aggressive ones warned him omegas were flighty, twitchy.

"Not safe," John managed petulantly, although his hands let go of the cover around him. One particularly deep breath, and he'd be exposed from the waist up.

"I … you're an alpha," John finished, his brain fogging over again as a second wave of heat hit him. His treacherous body was shaking from the proximity of the fit, virile alpha before him so obviously in rut.

"I am …" Sherlock's restraint considering the circumstances was incredible; John felt the anger and annoyance over the violation of his privacy fade slowly, as he let his baser instincts flood his thoughts.

"You can help…" John drew the covers away from his body. His sex flush had gotten worse, and his nipples were dark and peaked; his cock was achingly hard, although he'd just cum; he spread his legs, and the smell of slick became overwhelming.

"John, I … it's not safe. You'll get pregnant. I might try to bond you…" Although Sherlock shook his head, he sat on the edge of John's bed, chest heaving as he breathed in his scent as he toed off his shoes.

"It's fine, on the pill …"

"John," he nearly-moaned, as his hands reached towards the remaining buttons on his shirt, "are you sure?"

John reached forward, and grabbed his lapel roughly. "I swear to God Sherlock, if you don't plough me into the mattress and knot me, you'll be sorry."

"For fuck's sake, John," Sherlock replied in reverence, and gave up on the buttons, instead ripping his shirt off.

He ruffled his hair, scent oils contacting his hands, and pressed them to John's shoulders. Sherlock gripped him hard as John's hands worked his fly open. He tugged insistently on the trousers, and Sherlock pushed them down, along with his boxers and socks. Sherlock climbed over to him, between his legs.

Looking down at John's sizeable cock, Sherlock was so far gone he barely managed to get out the question: "Safe word?"

"No, we don't need-"

Sherlock interrupted, barking out, "Tell me or I can't let myself touch you!" His eyes were wild, and his hands shook with the effort of keeping them from roaming.

"Um... Liverpool," John complied, the effort of thinking nearly painful at this point, as he keened his hips upward.

With that, Sherlock closed in on him, bending his legs back towards his chest. He pushed a finger experimentally on John's hole, and slick leaked out, coating the digit. He brought it up to his mouth and licked it; his eyes grew dark, light irises eclipsed by pupils. He pressed the head of his cock against the slick pink hole, John making a positively submissive noise in the back of his throat. The alpha in Sherlock preened at this, growing possessive as he took John by his hips. With one great thrust, he bottomed out inside John, who stifled a cry.

Whether it was from surprise or pain, Sherlock couldn't be sure. He held the omega close, his rut warring in him to move, while his alpha instincts bared their teeth right back, ordering protect. He nuzzled his nose behind John's ear, and he heard John utter, "Make good on your promise alpha, and knot me."

Sherlock's hands moved quickly back to his hips, and began to move. The feeling was overwhelming, tight and slick and throbbing and so perfectly made for him. His delicate fingers gripped John's cock in his hand, and stroked in time to his thrusts. John was supple underneath him, his back bending to arch upward, craving as much skin contact as possible. His skin was soft and hot, sliding along the paler man above him.

Sherlock's thrusts were careful, measured. When John's eyes met his, he was startled by the look of concentration they held; how could he focus on anything when this feeling was so perfect? The brief pain was now gone, eclipsed by overwhelming pleasure. He felt himself spasm and clench around the alpha, a dry orgasm wracking his body as his fingers dug into the pale back above him.

Their eyes met again, and the look was gone. Sherlock looked like someone had just knocked the air out of him; his eyes were wide and his mouth parted in some unheard cry. His disheveled hair and the way he panted "John" were too much for him: With a strangled cry of "Sherlock!" John came, pulsing in Sherlock's hand.

The heady scent this added to the room was driving Sherlock crazy: "Oh God, yes… John," he moaned when he felt clenching around him.

He could feel his cock getting even harder, a sign his knot would be swelling up soon. John moved his hips just so, so the head of Sherlock's cock brushed his prostate. He threw his head back as a third orgasm was forced out of him.

The wild look in Sherlock's eyes returned, and he took John's hands from his back, and pinned them above his head. John struggled in earnest, but the alpha's strength rivaled his. Sherlock was babbling incoherently as he thrust deep into John, his knot beginning to swell: "…knot you omega, claim you as my own… make you my bitch…"

Anger flared in John's core, and flashed across his eyes. He linked his ankles together behind Sherlock's back, and broke the hold he had on his wrists. He grabbed Sherlock's back and rocked to the side, flipping them over. Sherlock was still thrusting in and out as if none of this had happened, his knot catching on the rim as it continued to swell. Soon, he wouldn't be able to move at all. John moved his feet to get more comfortable, and pinned Sherlock's arms to the bed.

"John H. Watson is no one's bitch, you got that?"

The effect his expression had on Sherlock was astounding. He recanted immediately, nuzzling into John's neck and murmured, "…just want you so bad, only you… not share you…"

He made a low whine in the back of his throat, the closest alphas were able to get to begging in this state, and with a final push, he seated his knot inside John.

The stretch against his walls burned, a spike of pain as he shifted to get comfortable against Sherlock's chest. He gazed down at the alpha just in time to see him come: Sherlock's eyes, which had been clenched tight as John rode through his orgasms snapped open. "JOHN!" He howled, words dissolving into small keening noises as his orgasm ripped through him.

John could feel himself being filled, this heat new and overwhelming. As Sherlock tried to thrust even as they were tied together he bent his head up, nuzzling against John's neck again. He breathed in deeply, scenting him. He broke the grasp John had on his arms and pulled John even closer, hugging him tight.

His eyes darkened further, and he licked briefly before he sunk his teeth into the tender skin of John's neck. John yelped at the sudden pain as Sherlock bit down, but he didn't fight. John knew a bonding bite only took if both parties wanted it, and despite everything that told him to resist, he wanted it. He must be mental, but he absolutely wanted to be Sherlock Holmes' mate. When Sherlock let off, he leaned back, John catching a momentary glimpse of blood on the tips of his incisors.

Sherlock lay back against the bed, turning his head to offer his neck to John in return. John leaned down, scenting his skin for a moment. He wanted to savor the scent of Sherlock, knowing his scent would change to John once he bit. He nuzzled against his neck, trying to find the best place to mark. His instinct welled up in him again and he licked the spot, a warning. His lips closed over the spot and he bit down. With his teeth sunk into the pale column of his throat, something changed. He bit hard enough to scar, tasting blood on his tongue. He held his jaw there for a moment, before slowly releasing his hold. When he came off, he felt different. His head was foggy like before, but it was not unpleasant.

He loosened his hold on John's back, and his hand sought John's. He laced their fingers together and they turned, each nuzzling in the crook of the other's neck. After awhile, John felt the knot inside him begin to shrink, and he was able to slip free. He shifted, settling in against Sherlock's side before falling asleep.