Chapter 1

The bus ride back from Camp Everfree was more subdued than the trip to it had been. All the events of the camp, dealing with Gloriosa Daisy in her magic-induced madness, left nearly every camper mentally drained. Though Rainbow Dash was sitting with her friends, none of them had anything to say that hadn't already been said.

Twilight, of course, was the exception that proved the rule. "I have his number, so I can just send him a text whenever I want, and he has mine too so—"

Rarity gasped in shock. "You gave him your number?" She stared at her friend until Twilight nodded. "Darling, you are seventeen! It shouldn't be too much of a problem so long as you keep to just being 'friends,' but he is a guy." She rolled her eyes, as if "guy" explained a whole host of things.

"I'll be eighteen in a month…" Twilight knew it wasn't a defendable argument, and sighed. "I just forget that you girls are all a year older than me. We are all going to be graduating this year, and I just wanted to—"

"Lose your virginity before college?" Pinkie's voice dropped into the conversation like a fifty-pound sledgehammer. She looked around at her quiet friends. "What?"

"That might be true, but one doesn't say such things." Rarity patted Pinkie Pie on the back. "Particularly not in public. Now Twilight, I am not saying completely forget about him, just that you need to tell him how old you actually are."

Rainbow Dash figured Rarity was the one to explain such things, and pointedly ignored the situation. Closing her eyes for a moment, she felt a happy dream slip into her head. She was riding her SonicBoom, screaming along the highway as if there was no speed limit. The wind streaked through her hair, and still she could twist the handle and go faster.

Just as her dream shifted into top gear, literally, she was startled awake by someone tapping on her shoulder. "Huh? What?"

"We're at school." Fluttershy's smile was not in the least bit strained by the long bus ride home, and she knew her friend needed a little something to offset the annoyance of being woken up. "Do you want a lift home? There might be room in the back for—"

"I'm good!" Quick to jump in, Rainbow Dash remembered the last time she had gotten a ride with Fluttershy. "It's not far to get home, and riding a bike makes it really hard to fall asleep." Not only did her panel van only have one seat (the driver's), but it was routinely filled with animals. Though it looked cute and colorful outside, Fluttershy's transportation was basically carpeted with animal hair.

Rainbow Dash hefted her backpack up from the floor and stood up. "Besides, it will wake me up a little."

The ride home had been boring, but just as Rainbow had predicted, it had kept her awake enough to reach home safely. Home, in this case, was a small house her parents owned, but she was allowed to stay in. Fumbling with her garage opener, she managed to get the button pressed just before her wheel collided with it. Rolling her bike inside, she turned the key and kicked the stand out.

A tap at the remote started the garage closing, and Rainbow stumbled towards the door that led into the house. Getting more tired by the second, she flicked through the keys and jammed the right one in and stumbled inside. "Ugh, this is terrible…"

Despite her lethargy, she saw to her pets first. Tank in his terrarium was still happy, the auto-feeder still three-quarters full. In the laundry, Thunderbolt was already jumping up on the door in excitement. "Hey boy!" Enthusiasm for her pet shepherd nearly matched Thunderbolt's own. "Happy to see me, huh?" Crouching down, Rainbow Dash ruffled the big dog's fur, and hugged his neck.

She spent five minutes making much of Thunderbolt, and the shepherd's enthusiasm for hugs never waned. But Rainbow had to jerk herself awake at one moment (only waking when Thunderbolt licked her face) and jumped to her feet. "I gotta sleep, boy. When I wake up we can go for a run."

Reluctantly, Rainbow Dash closed the laundry door again and headed for her bedroom. The sight of her bed, a big king-sized double bed, increased the weight the Sandman was putting on her eyelids. Kicking her shoes and socks off, she looked down at the bag in her hand and groaned. "I'll wash it all tomorrow… sleep time now…" Dropping the bag, Rainbow Dash took two steps towards her bed and fell onto it.

The girl was asleep before she even hit the soft, downy covers, and even fully clothed she managed to squirm under the covers in a daze.

Day turned to evening. Evening turned to twilight, and the Golden Hour started. Predators made use of the setting sun's light to hunt out their favorite food, while prey scurried towards their homes for the night. Rainbow Dash would normally be considered a predator—being a human, and so far above most other creatures as to barely see them—but tonight she had become the prey of a creature she had welcomed into her home herself.

Detecting the diurnal cycle entering the darker phase, a tiny worm grew active. Trapped inside something tight, it nonetheless detected a suitable target nearby. Squirming in the mud it had been living in, it slowly inched its way from one of Rainbow Dash's shoes—the one she had worn while searching around the mud at the lake of Camp Everfree.

The inch-long, thin worm hunted by the scent of carbon dioxide in the air. The prey it desired unleashed the substance constantly, which is how it eventually made its way up and onto the bed. Inching ever closer, it tracked the gas to ever greater concentrations, until it found warmth as well.

Stopping at Rainbow Dash's cheek, the tiny worm seemed to rear up and peek around. It didn't see, blind as it was, but it could feel the heat radiating from the girl's skin, and could taste the gas in the air. It was close to its prize. Pressing its soft tail to Rainbow's blue skin, the creature could feel the beating of her heart, and more importantly where a lot of the heat was coming from.

Moving with purpose, the worm passed the girl's ear, and inched its way down the her skin to the back of her neck. While its tail was soft and sensitive, the worm's mouth was anything but. It pressed its outward-facing teeth to Rainbow Dash's skin and started to twist them. To the sleeping girl, there was the most minute prickle of sensation before the creature's saliva numbed the pain. It worked onward, however, making the hole deeper, until its body could press into it and grip.

A tiny trickle of blood was soon the only indication that the thing had burrowed into Rainbow Dash's neck. The little parasite was excited—as much as such a simple arrangement of neurons could get excited—as it seemed to be approaching a major heat source. Breaking free of sinew and flesh, there was only one last barrier to its goal. Its teeth made short work of the first two layers of Dura mater, but while it could have plowed forwards, the parasite had evolved to protect its host. The quickly digested matter it consumed burrowing into Rainbow's head was formed into a glue-like compound, and used to seal the first layers of the Meninges behind it.

The Arachnoid mater was next, and then the Pia mater. At long last, it had found the organ of its host that suited it, it was resting against Rainbow Dash's Cerebral cortex. Again, its tail pressed down against the soft, fatty flesh, but this time it was sensing electro-chemical changes. Squirming slowly, it made its way between the soft flesh. It was seeking out an artery, hunting for the life-giving blood that would fuel it while it adapted its host to its needs. Sheathing its sharp teeth, it continued on its journey until it found a blood vessel that would be suitable. Opening its mouth for the last time in its life, the parasitic worm closed it around the side of the tiny artery and tapped it.

With the rush of blood into its system, a series of metabolic and metamorphic changes were triggered. The parasite's tiny mind flayed itself, sending tendrils of nerve fiber out of its body. Thinner than a strand of hair, the tiny bundles of tissue reached right into the dendrites of Rainbow Dash's own mind and found purchase.

One after another, the threads reached out to attach wherever they could, and while each of the initial ones did, the parasite's body seemed to meld with the blood vessel, becoming nothing but a blood-fueled neural tissue factory.

Dreams of motorcycles trembled in Rainbow Dash's head, and seemed to grow smaller. She felt a new calmness settle, stifling her dreams and putting her into a deeper sleep—a coma-like state. With the girl's mind subdued, the parasite started establishing a foothold on her brain. Tendrils located each of the lobes, some piercing the Meninges that separated each, and eventually reaching each and every part of her brain but one.

Last to be attached to, Rainbow Dash's brain-stem welcomed more neural tissue, integrating the many fine tendrils into itself, building pathways for them, and allowing a more substantial link between the girl's body and the parasite seeking to control it.

Hours passed where all the parasite did was grow more threads. It grew and stretched out until there was not more than a tenth of an inch of brain matter that didn't have a tendril bonding to it. It read details about its host's body, using parts of her mind to evaluate and decide on what course to take. Remapping some neurons would take time, and yet others would not be able to be remapped without the host's help, but it was completely confident in itself. It would definitely make this pony into what it needed.

Rainbow Dash's arm twitched. Then a finger. Then more. Slowly, the parasite started to map her body through her brain-stem. It had detected a problem, two actually, and Rainbow dash's own mind had given it the solution. Slowly, over the course of nearly an hour, all Rainbow Dash's limbs twitched and spasmed, but at last she rolled over.

On hands and knees, Rainbow Dash crawled towards her en-suite bathroom. Her eyes were open, sending input along the ocular nerves and into her brain. There, the parasite interpreted them and fed data through, providing a bypass to Rainbow Dash's own consciousness. Dragging herself up, Rainbow Dash managed to get her rear over the toilet, while her hands dragged down her shorts and underwear.

The rest of the muscles needed to correct the imbalance were practically automatic. The parasite held the girl carefully, not wanting to harm its host, and waited for her body to be done. A tickle of muscle memory triggered one hand to reach to the controls of the bidet, and in short order Rainbow Dash was back on her hands and knees—panties and shorts discarded in the bathroom—and crawling back to the bed.

Climbing back up seemed more difficult, and the parasite opted instead for a suitable alternative. Rainbow Dash didn't let Thunderbolt stay in her room often, but there was a dog-bed for times when thunderstorms made life unbearable for the dog. Slumping into the dog's bed, Rainbow Dash curled herself up into a ball and relaxed once more; leaving the parasite to its work.

Light streamed in through Rainbow Dash's bedroom window, and she started to stretch. "What the hay?" She was not in her super-soft bed, instead she was laying in Thunderbolt's doggy bed, and was completely naked.

Two needs filled Rainbow Dash: she was hungry, and she was horny. Laying in a dog bed was no way to solve either, so she climbed up to her feet and stretched. "I must have passed out here or something. Oh well, I don't think Thunderbolt will care." Ignoring a need for clothes, Rainbow walked out of her bedroom door and made her way through to her kitchen. She wasn't normally quite this brash about being naked in her own house, but being clothed seemed a lesser need compared to her hungers.

"Don't know what has me so worked up, I don't even think I dreamt… Oh well. Food first, then fun, then I can work out what to do with the day." Blue as the day she was born, Rainbow Dash grabbed a bowl from her cupboard and poured a bowl of cereal. A splash of milk and a little sugar, and she walked over to her kitchen table to eat.

Spooning up the crisp cereal, Rainbow Dash smiled and relaxed. Daydreams took the place of whatever other thoughts she wanted to process, and the hand not operating her spoon slid down and between her legs. In the girl's head, the parasite detected its second kind of food, and the primary training method it would employ. When inexpert fingers brushed down Rainbow's slit, the parasite drank up the pleasure the girl was feeling, the special hormones arousal was releasing accelerating its growth.

Her thoughts roamed at first, mostly thinking of guys, but then she turned to laying atop a car's hood while a guy sank his head between her stretched legs. Breakfast was slow, enjoyable, and Rainbow Dash continued to eat while her mind roamed free. The imaginary guy stood up before her, and before she could think further he was atop her.

The hand moving her spoon stopped, and Rainbow Dash focused on the other one. Rubbing harder, she imagined the guy pushing into her, and slid a finger into her depths. In her head, the parasite took mostly a background role in her enjoyment, triggering more arousal, but little else.

More and more she stroked, and at last she couldn't stop herself from imagining him finishing inside her, driving her to a very real orgasm. Squealing loudly, the bio-chemical reward of sex washed over Rainbow Dash, and despite the setting she squirmed and writhed in her seat. Trapped in the delicious afterglow, Rainbow gave a deep sigh of relief. The hand holding her spoon twitched, and she lifted another spoon load of cereal to her mouth.