Very belatedly taken from AO3 because... well, because. I would like to preface this story with the fact that this is dark. A lot of non/con and manipulative dub/con situations, which is why I elected to label this as 'horror'. Please be advised before you start reading, especially if alpha/omega storylines, consent-issues, and medical talk/kink are troubling to you. Otherwise, enjoy!

Oestrus Chapter 1

Whenever Hannibal set a plan in motion, he acknowledged that an element of unpredictability would govern its final course. It was something that he accounted for in his initial consideration. Half bred from indifference, half capricious in nature, it at the very least would soften the blow if—due to the fickleness of fate—his plot never came to its suitable end. A true empiric vanguard, Hannibal was seldom disappointed with any outcome, as long as he could observe it uninhibited. Rarely, however, did fortune bestow her gifts upon his plans to allow for such a result.

Hannibal had timed it perfectly.

It had all started with an errant comment—a throwaway piece of information shared due to the lack of perceived threat. Had Will known it was to be filed away and kept almost covetously until given a chance to bloom, then he would have never admitted to Hannibal that his heats were unusual. During one of their not-quite-therapy sessions, Will had mentioned that the next week's meeting would have to be postponed. As this was just a meeting between friends—over drinks no less—he held no reluctance in admitting that it was because his upcoming heat was scheduled to fall over their allotted time.

Since Hannibal knew that Will was an omega—his gender known by all throughout the FBI—this was not especially notable in any way. With eyes lowered to the flickering fireplace and voice deepened with wine and late night conversation, Will had revealed that he experienced exceptionally short heats. So short, in fact, that they could schedule a meeting just a couple of days after its start.

In less than forty-eight hours after his heat's onset, Will's hormones would find their balance and his cycle would start anew. It just so happened that that would bring them to Friday evening, so Hannibal did anything a gracious host would do and invited him over for dinner.

Although the conversation that night—and Friday's—never once returned to the topic of Will's heats, it never quite left Hannibal's mind. Always at the periphery, the weight of this privileged knowledge was nebulous throughout the weeks until an idea started to form.

As an alpha, Hannibal could appreciate the oestrus cycle of an omega for what it was—a length of time where within the omega was receptive to their alpha's advances and the alpha sensitive to theirs. The longer it lasted, the higher the probability of their coupling resulting in pregnancy. Most omegas would average heats that lasted up to five days, but the longest one on medical record lasted for an interminable twenty-one days.

Twenty-one days was long enough that the omega in question, bred long and hard under observation, took as much alpha seed as possible.

Alternatively, just under forty-eight hours was hardly any time at all. To have such a long period of sexual rest between heats was curious indeed, especially in one as seemingly as healthy as Will. It was a puzzle that did not necessarily beg for an answer but one that Hannibal was determined to unravel according to his wishes. For the 'why's were not pertinent when the 'hows' were rather much more interesting.

This was how Hannibal began to disappoint the upper echelons of Baltimore with fewer and fewer dinner invitations, as he spent less time stocking his fridge and crafting elegant meals in lieu of building his strategy from the ground-up.

Developing a drug regime that had a short half-life was necessary for his manipulations to remain undiscovered; however, a rapid clearance would require regular dosages. Thankfully, the colourless, odourless, and tasteless powder was easily slipped into water shared over meals. And if—because of Will's hectic work life and his barely concealed desperation for companionship—Hannibal was able to provide most meals, then far be it for Hannibal to complain.

Hannibal knew that Will's next heat was to arrive on the Tuesday, and with the medication, Will's heat should last for much longer than 48 hours. For how long, he could not guess; but with any drug trial, it would be repeated for many months until the desired results were produced. After such a time, Will would confide in Hannibal the confusing changes he was experiencing. If he was lucky, Hannibal would one day see them first hand.

What Hannibal didn't account for was that the Monday before Will's heat, his classes went on break. At the same time, and perhaps due to Hannibal's own preoccupations, Jack had no murders for which to call upon his bloodhound. When Will missed not one but two of his scheduled meetings with Hannibal, the doctor did everything within his power not to visit his not-quite-patient unannounced; for a good plan was one that unfolded organically, and he remained vigilant that Will would be the one to come to him.

That is, of course, until this morning, when Jack asked him to accompany him to Will's house in Wolf Trap. Jack had called Hannibal out of frustration, asking the doctor if he had had any contact with Will. Jack had left several increasingly demanding voicemails himself with no luck, and after being thoroughly ignored, Jack's patience had ran so thin it shattered. When Hannibal revealed that, no he had not seen or heard from Will in weeks now, and in fact Will had missed dinner twice, that was the last straw. Jack had growled then, thinking Will was purposefully withdrawing from his responsibilities, so he had demanded that he drive Hannibal to Will to see if the profiler could account for his absence. Or at least, Hannibal mused, as much as a beta could demand of an alpha.

Which is how Hannibal found himself standing before Will's house, basking in the knowledge that Will— irrevocably altered by his hand—was just beyond the door. The house yawned with Will's presence, hidden away behind walls and insulation. It throbbed with an intensity, and like a tuning fork, Hannibal found the fibres of his being harmonising. Nerves alight with anticipation and the thrill of ambiguity, Hannibal revelled in the fact that until he crossed the door's threshold the extent of his influence was unknown.

The scene that greeted them was grim. The door had its screen pushed out from the inside—an obvious makeshift passage made by the dogs that now ran towards them. Their whines complemented the flat crunching of soil underfoot as they surrounded the two men—their distress as apparent as the dark mud covering their coats.

"Doctor—" Jack warned, gun drawn and walking slowly towards the door, mistakenly thinking that the scene was of something criminal in nature.

Jack knelt down and cautiously unlocked the door through the broken screen before he stepped through. Hannibal was happy for him to lead the way, only entering when the man repeated his title.

A hand braced against his chest before he could cross the threshold, but it was too late. Hannibal's nostrils were already widening to scent the pungent odours of dried slick and sweat.

"I don't think you should be here," Jack said, meaning that as an unmated alpha Hannibal had no business being near to Will at this vulnerable time—suggesting that Hannibal had as little self-control as a newly gendered, hormone addled alpha and would ravage the unsuspecting omega even with Jack as witness.

Hannibal barely contained his sneer at Jack's doubt but only just. Hannibal could and would withstand the temptation that was Will. For now.

"He is my friend," Hannibal said, eyeing the arm still blocking his way, "and as a doctor my only duty is to see him well."

Hannibal's stoicism and steady voice convinced Jack that his words were heartfelt, and he was allowed in.

Inside was magnificent. The room was humid with pheromones, and Hannibal could feel them beading in a moist layer over his skin. Everything that was Will—the complex odours of heat, thick and saccharine, coupled with the tang of slick, cum, and sweat long since dried was something Hannibal wished to smell to their source, following his nose until it found the skin that was pumping out these hormones; but with Jack watching, all he could was to catalogue each molecule to be remembered later in privacy.

The room was a mess—disorder barely contained. The pillows fallen from the chairs suggested Will had at one time sat on them before his fever became too much to remain upright. An overturned cup with some water still in its glass lay next to a cereal box—its plastic bag half pulled out and trailing sweetened flakes onto the floor—was a meal abandoned. Following their wake, the comforter was tangled at the foot of the bed where some of the dogs remained curled, heads cocking at their guests. The one Hannibal recognised as Winston whined, obviously confused and hungry. The dogs' bowls had been licked clean.

But it was the figure that lay on the bed that arrested his entire attention. Naked save for the sheet twisted between his legs, Will lay unmoving on his stomach with his face turned away from them. Coming to the edge of the bed, Hannibal could see that unseeing eyes were open a crack. He was so still, for a moment Hannibal's chest restricted; it was only when he saw the rise and fall of Will's that he was assured he was even still alive. Hannibal took a moment, taking in the sweat-dampened tangle of curls fanning over the pillow case, the miles of unblemished skin, and the dark sweep of eyelashes contrasting against flushed and gaunt cheeks. He was remarkable.

It was during his study that he noticed the subtle flare of Will's nostrils.

He had finally scented Hannibal.

The whites of his eyes rolled before deep blue latched onto the herringbone of Hannibal's suit leg. Will flung out an arm, blindly trying to grab Hannibal's knee as his hips rolled weakly—his lower back just barely tilting in an attempt to present. A suffering and sharp omegan whine rushed through parted lips before it dried out in a rasping croak, choked off despite his desire to entice the alpha before him.

Decency dictated that he stay out of Will's searching reach, but he longed to touch Will—to strip himself of his suit, cover the omega with his body, and bury himself deep until his knot locked them together. The pull of it flickered low in his belly even though the whine hadn't been full, which made Hannibal wonder how powerful it could be. He took a step back for propriety's sake, as Jack took a protective step towards the bed.

By the roving eyes and slack face, Hannibal knew Will was barely conscious of his surroundings, having little awareness that he was reaching for Hannibal or even why his body made him do such things. Will's upper lip was glued to his gums in a snarl showing off sharp, parted teeth, and Hannibal appreciated the feral look it afforded the omega; but he realised it—along with how Will was no longer sweating or producing slick—was a testament to how truly dehydrated he was. The poor man, after two and a half weeks in heat with only the company of his dogs, had been left adrift.

Hannibal allowed the events leading up to this one play within the pinhole of his mind. Will would have been prepared for the first few days, as it still fell within his normal duration. Hannibal imagined him coping with his affliction with a remote efficiency—neither taking pleasure beyond the orgasms he would have managed to achieve on his own nor lamenting in his sentence as an omega in heat. He would have stocked his fridge, fed his dogs, and made to wait through his heat with the practice of a mature omega.

The first extra half day would have gone unnoticed, melting away along with Will's concept of time during his heat. But when hours turned into days, he would have realised something wasn't right—that the dogs were whining more than usual, that his body was hotter—more tired—than usual. As time dragged on, so too did the fever. It would have been impossible for Will to comprehend how precarious his footing was as he followed the path of his heat for longer than he had ever done before. The fog of hormones, after days of building and crashing upon themselves, would have worked to overwhelm his system. Will would have found it hard to think beyond the holy trinity of need, desire, and lack; and as his fever burned through his body—made tired by his desperate ministrations to cool and fill it—would have blazed through energy reserves until he couldn't care for himself, his dogs—until he couldn't even leave his bed.

Dark circles bruised the thin skin underneath his eyes, speaking of the endless nights kept up by his excessive longing. The soiled sheets dried with cum, slick, and sweat displayed Will's valiant effort to quell it, but as weeks went without sustenance his body merely did not have the strength to comply. His heat stalled right at the precipice without the relief of climaxing, and Hannibal was amazed to see that his body continued to punish him the longer it was kept there. He was equally astonished to feel the beginnings of regret. From some primordial crag within his being, Hannibal felt the tug of his alpha instincts. He should have been available to provide for the omega.

Under Hannibal's scrutiny, Will's undulations devolved into uncontrolled jerks, looking more like a weak fit than any attempt at presenting. His chest hitched and his mouth twitched, signalling another failed attempt to whine before the alpha. Hannibal was relieved that that his parched vocal chords were incapable of vibrating, as that particular sound would have upset the veneer of calm Hannibal had cultivated. Incapacitated and desperate and wholly omega, that sound would have challenged Hannibal's ironclad reserves.

Even still, he found himself placing a broad palm across Will's exposed nape, absorbing its warmth. Will stopped his useless convulsing, melting bonelessly under Hannibal's hand with a sigh. When Hannibal squeezed the tense muscle, Will's eyes fluttered close in something akin to peace.

"Doctor, what's going on here?" Jack deferred to Hannibal as a physician and as an alpha. As a beta himself, he had very little exposure to omegas and their heats. He knew enough as the head of the Behavioural Analysis Unit to read the clues that littered the room and understand that they pointed unequivocally towards heat, but he lacked the particular receptors to decipher the sweet smell laced with a heady and intricate balm of chemicals. The pheromones secreted into the air were meant for Hannibal alone, and he breathed deep to take it all in.

"Will had cancelled his meeting with me all those weeks ago due to his scheduled heat, but as he confided in me then it should not have lasted more than a few days," Hannibal said, moving away from the bed and turning towards Jack, "It appears dear Will is still within the throes of his heat, weeks past its presumed end."

"It's been nearly three weeks. A heat this long… isn't normal," Even a beta knew that, "So why is this happening?"

Hannibal took a deep breath, overcome with feigned ignorance, "Any number of reasons. From outside stressors to internal imbalances laying waste to his biology. I cannot determine it beyond that it must have been a significant trauma to manifest in this way."

His words were purposefully selected to suggest that this was a normal occurrence with heats—that omegas regularly suffered upset to their cycles due to anxieties—anxieties that Jack encouraged with every phone call.

"Is this my doing? Did I break him?" Jack asked, eyes pinning Hannibal with hard stare, already weighted with blame.

"If so then we share that guilt. For if your dragging him to crimes scenes devastated his defences, then it was my negligence as his friend and a psychiatrist that let them crumble completely. I should have known to check him after he didn't arrive when he had promised. It would have saved us—and Will—considerable grief."

"You couldn't have known," Jack said as he pulled his cell phone from his pocket, "This man needs a hospital."

"Jack," Hannibal couldn't allow him to call for an ambulance that would whisk Will away and undo everything that he had created.

At his name, Jack stopped dialling and let his thumb hover over the screen. When he knew he had his full attention, Hannibal made sure to look like he was struggling with his words, "We must consider the care that awaits Will at a facility equipped to provide for omegas. I fear he may never forgive us if he wakes up there."

While true that he would hate waking up in an omegan hospital, Will was intelligent enough when lucid to understand the medical danger he was currently in; he would want to find relief wherever it may be found even if it was in the walls of an antiquated hospital. These hospitals had barely advanced along with omegan rights and were known for distressing examples of gender inequality and questionable care. It was a fact that Hannibal knew would force Jack to reconsider.

Will would find his relief in Hannibal yet.

"Then what alternative do you suggest?"

The alpha within unfurled, replete and heavy under the surface of his skin. He thought Jack would never ask.