Zecora had been quick to supply Rainbow Dash with some ointment for Fluttershy's crispened skin before ushering her out the door. She hated that she had to act so curtly, but the medicine mare needed all her focus at hoof to prepare the cure for her friend's affliction. She had most of the ingredients now and surmised that the crucial herbs from her homeland would arrive before much longer. Regardless, Zecora had begun preparing the base for the potion ahead of time, knowing that the final crafting process could take a while and that every second she could shave off was more time for Fluttershy.
Sweat beaded on her forehead as she loomed over her cauldron, stirring the brew and occasionally jetting back to her reading desk to rustle pages in the archaic tome that bore her recipe. Zecora wasn't sure if she had ever put this much effort into a single concoction in her lifetime, but she knew she didn't have the time to ponder. She kept the fire going all hours of the day and night, keeping the magical stock bubbling and hot and the air of her dwelling as heavy and humid as the jungles of her homeland.
"I must keep at my work and spare not a breath," Zecora thought as she labored. "or condemn Fluttershy to a fate worse than death. Still, when the young mare is once more mild and meek, I shall take to my bed and stay there for a week..."
While Rainbow Dash sped off to Zecora's hut, Fluttershy sat sullenly on her bed, carefully staying away from the window's rays, and collected the feathers she'd molted during the night. She half-heartedly counted them, more focused on the increasingly visible webbing that was taking their place. The hooked claws on her wings were fully in, and it wouldn't be too much longer before her wings were completely bare. The thought of what was happening to her felt like a stake through the heart, and she probably would have let herself cry if she hadn't noticed something else: mixed in among her own plumage, a fluffy, powder-blue feather, one of Rainbow Dash's.
Fluttershy gave a small smile, barely noticeable, as she held it up, making her nose twitch with its faint scent.
"Oh, Rainbow..." she thought. "You've been with me through all of this... actually, you've been with me for a lot longer, through thick and thin since we were fillies... I never want to be withou..."
Fluttershy tried to finish her thought, but for some reason the ending wouldn't come.
"W-Without... with... wih..."
A strange feeling overtook her faculties, as if something were creeping up and slowly consuming her mind. Her words turned to images, to feelings, to lived experiences with their sights, tastes, and smells. All thoughts of Rainbow turned to her shape, her movements, her overwhelming sensory presence; Fluttershy felt her heart beating faster and her body responding to it. She could sense Rainbow's traces as though she were sitting next to her - how she smelled, her physical health, and especially the pheromonal cocktail that drove a primal hunger deep within Fluttershy, a hunger not of the stomach, but of the loins... or... perhaps both?
Suddenly, Fluttershy felt back in control. The odd sensation disappeared, as if something inside had snapped her back to normal. She could think in words again. Before she had time to process the strange occurrence, Fluttershy's attention was once again back on the feather, and her mind drifted from Rainbow Dash to the rest of her friends.
"They must be so worried about me..." she thought. "I can't imagine what Twilight or Rarity or Pinkie Pie must be thinking right now. I wish I could see them, to tell them I'm okay, but I g..."
She trembled. Something wasn't right.
"G... gah... I gah...g..."
The feeling of loss returned. Once more, she could sense her friends as if they were in front of her, but the concept of 'friends' wasn't registering. Instead, she once again fixated on their condition, their every strength and weakness. The ones with horns emitted especially strong magical auras and would be dangerous. The two without horn or wing would be easiest, she felt, and each had their challenges and benefits. The orange one was especially strong, but also especially lean and vital; if she could be brought down, she would provide excellent fuel in her currently weakened state. The pink one, on the other hand, was soft and vulnerable, if very fast; if felled, her own stores of fat and energy would prove useful once the snows came...
Fluttershy snapped back into her own thoughts, but the foggy feeling didn't completely leave. Everything around her seemed blurry, distorted in some way she couldn't identify. She tried to tell herself she needed to go back to bed, but the message was garbled; something about 'bed' didn't quite make sense. Then she thought maybe she needed water and looked over next to her... but the water was in some strange thing, not a stream or pond like it should have been. And it was next to an even stranger, shiny thing that made a steady ticking sound. Its little whiskers moved slowly upon its flat face, and it didn't have the sense to cower from her. Where even was she right now...?
Once more, reason returned, though her short-term memories were oddly missing. She recognized Angel, however, and beckoned him to come and snuggle with her. The little rabbit gave a careful hop across the bedspread towards her, but in the blink of an eye he was recoiling in fear. As he hopped down and sped out of the room, instinct told the mare to pursue him, but she was too physically tired.
Any words that tried to form in her mind died and fell away before they could be realized. The room began to spin. Sounds, smells, thoughts, experiences. Everything blended together into a fugue state that felt both comfortable and distressing, natural and unnatural, dominant and passive. If she did try to process what was going on, she didn't succeed before she lapsed out of all awareness.
What came afterwards were sensations more than anything else.
Heat. Coolness. Quiet. Noise. Calm. Violence. Stillness. Movement. Pleasure. Pain.
And then she fell asleep.
At first, Rainbow was terrified, dashing to Fluttershy's side to make sure she was still alive and breathing. Assured of that, a moment followed to catch her breath and allow her confusion to dawn. How had Fluttershy wound up stranded in one of the Everfree Forest's many shaded groves, passed out on the ground with a head wound and a trail of bedsheets behind her?
A brief look around the crime scene coupled with some inductive reasoning powers she'd picked up from Daring Do books allowed her to hazard a guess. Clearly something, whatever it was, caused Fluttershy to bolt out of the house, and the blankets must have protected her from the sun. The scattered trail of linens showed she had wandered around, or was tracking something... to eat? Some torn-up earth and a mass of hoofprints nearby showed there was a struggle. Looking closer, Dash found cloven hooves among the familiar pony tracks - probably deer. Two different sizes of track indicated more than one - a parent and child. And since Fluttershy was unconscious with a gash above her eye, it stood to reason she'd taken one or two swift kicks in the botched hunting attempt, allowing her prey to escape.
Rainbow slowly shook her head as she alighted and knelt to pick up her sleeping friend, careful to both keep her covered in blankets and avoid the acidic blood weeping from her brow. The flight back to the cottage was slow and careful as Dash made sure to avoid any large patches of sunlight, all the while thinking on the situation in which the two Pegasi had found themselves.
"What are we gonna do, Fluttershy?" She asked as though her friend could read minds. "If Zecora doesn't get that medicine mixed up before long... no, I'm not letting my mind go there. We'll just have to keep hiding this... making sure nopony sees you... and that you can't hurt anything..."
Rainbow let her thought trail off as she realized how impractical it would be, but steeled her resolve nonetheless, focusing on getting Fluttershy home instead of giving in to despair. When she finally arrived at the front door of the cottage, she couldn't help but notice how eerily quiet it all seemed without any animals present. No singing of birds, no buzzing of insects... even Angel Bunny was nowhere to be found. It was as though life had left that part of the Everfree as undeath crept into its shepherd.
Dash silently bore Fluttershy over to the sofa, leaving her cocooned in disheveled sheets and pulling all the blinds in the room as tightly shut as they'd go. She carefully cleaned and bandaged the cut above her friend's eye without waking her from her pacific sleep, and likewise applied the aloe vera to the opposite, sunburnt side of her face. Dash watched her for a moment, observing her breathing to make sure she was truly alright. She tilted her head to the side and ran a hoof through her rainbow mane in worry. Her mind wandered to happier days of yore, her heart welling up with the wish that they could return to them. She hoped beyond hope that Zecora's medicine would do the trick, and that it would be ready soon. Even though she tried to put on a brave, optimistic face, deep down, Rainbow worried, and she didn't know how much more she could take.
Nonetheless, she thought, she had done all she could do for now. It was probably best that Fluttershy get her rest anyway. Quietly hovering to another corner of the room, Dash quickly found a nice soft chair and began catching a few extra Zs herself.
It never surprised Rainbow Dash that she could sleep most of a day away. Even if she seemed perfectly well-rested, the mare possessed the innate talent to drift off to sleep just about anywhere she thought looked comfortable. Many were the days she spent curled up on a cloud drifting over Ponyville, having lulled herself asleep thinking about Pinkie Pie listing every single type of cupcake or Twilight lecturing on Haycarte's Circle Theorem. So naturally, it was no surprise that she'd found it easy to sleep in one of Fluttershy's antique parlor chairs, the fluffy cushions and oddly textured upholstery cradling her like a nice stratocumulus.
What was a surprise was the fact that Fluttershy had since woken up and was hovering mere inches from her face.
Dash's eyes opened slowly at first, then immediately popped the rest of the way up as soon as they spotted the yellow and pink shape bobbing up and down before them. She immediately threw her body back with a less-than-calm noise, bringing the chair with her as she careened towards the floor. A quick roll right-side-up allowed her to pop open her wings, ready for anything... but instead, Fluttershy simply floated there as if nothing was wrong. After a second or two, she did pick up that something had just happened that startled her friend.
"Oh! I-I'm sorry... did I scare you?"
"Fluttershy! Yes, you scared me! Why were you just floating there, staring at me from inches away?"
"Um..." Fluttershy put a hoof to her mouth and glanced around the room but seemed to lose her train of thought very quickly. Instead, her attention turned back to her own hoof, which she began licking and grooming as a cat would.
"Fluttershy, come on now." Began Rainbow Dash, slowly approaching her. "I'm not mad, I just don't know-"
Before she could reach out to rouse her friend from distraction, however, the mare's eyes grew narrow and fixated upon her. Suddenly, Fluttershy lashed out, snarling at Rainbow Dash and baring her fangs, slick and glinting in the evening candlelight. Dash recoiled again, her ears pinned back and her hooves retreating a few steps.
"Fluttershy...?"
Hearing her name uttered in Dash's nervous tone must have triggered something within her, for Fluttershy alighted upon the floor and carefully moved towards her with gentle eyes and a submissive posture. Almost tiptoeing, she took care to wordlessly reassure her darling that everything was fine. The blue Pegasus couldn't help but let her guard down a little as Fluttershy nuzzled up against her cheek so lovingly, moving on to rub her own mane against hers...
...But what started as affectionate quickly became awkward, then unnerving.
"Uh, Fluttershy?"
Said mare worked her way down Rainbow's body, rubbing her ears and cheeks across her shoulders, her torso, her wings, as though she were claiming her for herself. Normally, Rainbow wouldn't have complained, but something didn't feel entirely right, entirely genuine about this attention she received. She was briefly distracted as Fluttershy's tail flicked in her face. The mare rubbed herself against the Cutie Mark on her flank, and then her focus very quickly turned elsewhere, her sniffing snout attempting to probe places that made Rainbow blush.
"H-Hey! What's gotten into you?!" She very quickly spun her rear away from Fluttershy, confronting her with a furrowed brow and reddened cheeks.
"Now look, I know your instincts have been getting stronger and stronger, but you need to try to fight th-"
Before Rainbow had realized what had happened, Fluttershy had done something completely unthinkable to her normal self: she'd stepped forward and put her tongue in Rainbow's mouth. What was thrilling nights ago became upsetting in a way she'd not known before. Rainbow squirmed and shot her eyes around as their muzzles pressed together but decided to at least try and enjoy it for Fluttershy's sake, shutting her eyes with a look of discomfort still writ across her face. As Fluttershy plied her lust at Rainbow's mouth, she slowly unfolded leathery wings and wrapped them around her, not a plume to be found as she cradled her treasure.
Then, almost as quickly as the kiss had started, Fluttershy pulled away... and lunged for Rainbow's throat.
Fortunately, the Wonderbolt's instincts acted quick enough to whisk her out of the leathery wings and towards the ceiling, narrowly avoiding the strafing fangs. An angry hiss emanated from Fluttershy's throat as her lover-turned-prey escaped from her clutches.
"FLUTTERSHY!" Rainbow scolded. "DON'T do that! I told you to fight it! If you're hungry you can just ask me."
From her lofty position, however, something once again seemed to have changed in her friend below. Fluttershy staggered, a hoof grasping her head in pain as she flattened her ears. Rainbow was much more cautious in her approach this time.
"Fluttershy...?"
Said pony tried to look up at Rainbow Dash, but found herself disabled by her seeming headache.
"Ngh... D... D-Dashie...? I... aah..."
Dash carefully hovered low to the floor, brushing aside Fluttershy's hoof and mane to look in her eyes. Though they turned from blue to red some time ago, now even her sclerae seemed pinkish and bloodshot, almost as if an infection was setting in.
"Fluttershy, do you remember anything that's happened in the past few minutes?"
"N... N... No..." She continued to tremble and hold her head.
Rainbow Dash felt a nervous sweat break out on her forehead. There wasn't much more holding back she could do; if Zecora didn't have her medicine ready and soon, there would be nothing left to save.
She needed to watch after Fluttershy... but she also needed to keep herself safe.
There might be a solution, she thought.
"H-Hey Fluttershy?" said Dash, just above a whisper. "Back when, um... when the bat bit you...? You know, when this all started? Where did that happen?"
It took the mare a minute to comprehend what was said and find the right words to respond.
"U-uh... i-in my sewing room... I-I..." She gestured towards her front door. "I found the bat o-out there... ngah... a-and I took it... down here..."
Unsure of who was leading whom, the two made their way towards the secret sliding door to Fluttershy's underground knitting room. Rainbow let her go ahead down the stairs to continue her tale, but she didn't follow. By the time she realized she was alone and turned around, Dash had already slid the door back.
Though the door was hard to distinguish from the wall surrounding it, Dash made sure she secured it properly; having quickly retrieved a hammer and nails from elsewhere in the house, she nailed one end of a wooden board into the door and the other end into the wall, ensuring it could not be slid open. Fluttershy's voice from within sounded like she was being buried alive.
"RAINBOW DASH, HOW COULD YOU?!" she sobbed aloud, screaming to be let out, straining her voice until her cries sounded like gravel.
It tore at Rainbow's heartstrings, and she herself began to cry as well, even as she nailed more spare boards onto the door. She knew that she could do nothing to help her friend, and she knew that her own life was in danger if they continued to be in proximity. As difficult as it was, Rainbow continued to shut up the love of her life in an underground cage, awaiting the time she could be cured.
When she ran out of planks, Rainbow curled up against the door and bawled like a child.
Zecora paced around her cauldron, occasionally lifting the lid to check its simmering or poking the fire to rekindle the ashes. All she needed now was that last ingredient, the precious dried herbs from her homeland. She hoped they could still be found, that they still existed; it had been so long since the vampiric affliction had last struck, she wasn't entirely sure if they could be. Nonetheless, she kept both ears well open, eagerly listening for any kind of knock at the door...
Or a crash into the upper branches of her arboreal home. That worked too.
Rushing to the front door, the zebra turned her head this way and that before finally being alerted, by gently falling leaves, to the presence of Ponyville's cross-eyed mailmare above her, tangled in the foliage.
"Uhhhhh.... Zecora?" she spoke with an innocent, slightly congested voice. "There's a big envelope here for you."