"Cool, let's do it, " said Amy excitedly, as she began to open the box.
Mary slammed it shut. "Whoa, whoa, whoa. I think you have done enough transforming for one day. It's not safe. Besides, at least one of us needs to be human so we can hold the box for the trip home, " said Mary.
"But I'll freeze, " said Amy, pretending to shiver.
"I think my fur and body heat should keep you warm enough until we get to your farm. I need you to guide me, and to help me become human again when we get home. Can you do it?" asked Mary.
Amy smiled very widely.
"Oh, yes. I can do it. Go ahead, get started, " said Amy eagerly. She wagged her hand, encouraging Mary to open the box and drink the vial.
Mary was a little perplexed by Amy's sudden compliance. She had expected a lot more resistance from the girl, and had planned on giving her another speech about responsibility and the greater good. But she was not one to look a gift horse in the mouth. If Amy was willing to help, it was all the better. Mary opened the box, and found the horse vial. Watched by Amy's wide eyes, she downed the entire contents of the "Horse" vial.
Mary gradually got warmer, as her thick brown coat grew in. She felt her legs get thicker and stronger. She fell to all fours, as her chest rapidly expanded and her breasts receded into her chest. She shifted uncomfortably as her toes lengthened and merged. Her nails thickened into a hard black hoof. She shook her head as her neck lengthened and a dark black mane grew down her neck. Finally, her face ached as it shifted into an equine muzzle. After several minutes, a large horse stood where Mary once was.
"Wow, that was so cool, " said Amy, as she walked up to Mary. "And you are so beautiful."
Mary flipped her long black tail in appreciation. Amy rubbed Mary's muzzle, just like she did to the other horses on her farm. It felt good to Mary, and she involuntarily stamped her hoof in pleasure. The loss of control shocked Mary, and she shook her head and backed away from Amy.
"What's the matter, girl?" asked Amy. She suddenly felt very cold. "Oh yeah, we need to get out of here."
Amy grabbed the box and mounted Mary. Mary bent on one knee to make it easier for the small rider. Amy was an experienced rider, and they quickly made it down the mountain. Amy guided Mary with her feet as much as her voice. Mary quickly picked up what the slight changes in pressure on each side meant. She didn't really like it when Amy dug in her heels, and Mary snorted her displeasure.
"Sorry, Mary. Sometimes I forget, " said Amy innocently.
After several hours, they approached the farm. It was getting dark, and Amy could see several police cars in her driveway. Her Mom was tearfully talking with a police officer, and ran towards her when she saw the young girl approaching on horseback.
"Amy, where have you been?" said her Mom angrily. "And why are you naked?"
Amy's Mom pulled her off Mary's back and hugged her. Amy held tight onto the wooden box. One of the officers produced a blanket, and covered her up quickly.
"Hey, who's horse is that? I've never seen that one before, " asked her brother. He looked a little roughed up. Amy assumed the hunters had not been happy with his information. Or maybe her Mom was not happy with his poor babysitting skills.
"It's my horse, " said Amy proudly. "I found her in the woods, and she helped me get home. Her name is Mary."
"Well, thank you, Mary. We appreciate your help. John, why don't you put her in the stable with the other horses?" said her Mom.
John slipped some reins over Mary's head. Mary snorted and bucked, causing the reins to slip in John's grasp. She didn't want to be a horse any longer. She whinnied angrily at Amy. She wanted her to just tell the truth, and use the vials to return her to human form.
"Whoa, girl, whoa, " said John angrily.
"Mom, it's my horse. Let me do it, " said Amy.
Her Mom looked at her sternly and took her by the shoulder. "I think you have spent enough time outside with that horse. Your brother is more than capable, and he will take good care of YOUR horse. You need to get inside and get dressed. What did you do with your clothes anyway? Sometime I really wonder about you, " said her Mom.
Amy gave one helpless look back at Mary before she was drug back into the house by her mother, carrying the box with her.
Mary was dragged herself into the barn. She tried to please John, but he seemed upset by the situation, and was taking it out on her.
"Stupid Gryphon, flying away like that. Stupid Hunters, not my fault they couldn't catch it. Stupid sister, running away to play with dumb horses, " mumbled John, as he tugged hard on her reins. He led Mary into a pen in the barn, and stood beside her flank.
"No brand, huh? I guess you really will be my sister's horse. But I am going to be the one to brand you, " he said wickedly, as he slapped her flank hard.
Mary whinnied and reared up. John quickly backed out of the pen, and locked the gate. He gave one glance back at her, staring at her strangely, then left her alone in the barn.
Well, not entirely alone. There were several pens lined up along the walls, each filled with a different horse. They each smelled a little different to Mary, and she could tell that some were male, while others were female. Her stomach rumbled. She looked down and saw that John had left before filling her trough with food. Not that she was particularly looking forwards to eating oats, or whatever it was that horses ate. So she just stood staring outside the pen, pondering what to do next.