Before your eyes clear you can tell you're somewhere where they keep horses. When your vision does return you can see that you're in a horse stall with the door closed. You walk up to it and try to push it open but you find it latched on the other side. Still in a state of heightened arousal you try to reach through the gate and undo the latch, but your fingers are stiff and you just end up fumbling at the latch uselessly. You snort a bit in frustration and back away from the door, hands clenched in frustration.
You can't concentrate like this. You decide that there's nothing for it but to relieve this pressure on your own. You move your hands to your belt buckle, but you find that your hands won't unclench. Try as you might you can't force your fingers apart. You let out a cry of frustration that turns into surprise as you see your fingers begin fusing together and a hard black film covering the backs of your hands. Your hands appear to be turning into hooves. You cry out for help, but the words come out awkwardly, as your teeth shift and you nostrils widen. You focus on your hands and can see dark brown hair spreading from beneath the hooves that once were hands, and you watch as the muscles shift and bones stretch and change. Your focus changes to your nose when you see it stretching out before you. Your head gets larger and your hair begins growing down your neck, which starts to lengthen.
"Ah...there you are." you hear a familiar voice. You look up and see that woman you had stumbled in on. She's changed her clothes, now wearing a simple, if oddly out of date, blue and white dress, her curly black hair done up in a bun and tucked under a broad-brimmed hat. Your vision goes blurry and as your eyes shift and you can feel your ears extending above your head into flexible points.
"What's happening?" you try to call out through your shifting face. She only smiles in response. Unbidden you feet rise up on the balls of your feet. You can feel your back legs growing and your feet turning into hooves just as your hands have. You rear expands exponentially and your tailbone forms a bulge grows out into a horse tail. You groan in pain as your pants begin to restrict you. Soon your hear the sound of your pants splitting at the seams. It's a relief when they finally burst and your tail flops free. Your chest barrels out and lengthens, and you feel your back snap into a different position, your feet lengthen. Your arms are long now and brown hair covers your entire body.
Your arms are long now and your have to bend them in order to keep your balance. You're trying to stay standing on your back legs, whinnying in fear as you do, but you can feel gravity pulling you. You can hear her laugh as you try to keep your upright balance. You can't fight it any longer. Your front legs, for that's what they are now, fall to the floor with an audible clop. As all four hooves touch the ground you can instantly feel any remaining changes finish. You crane your long neck back to look at yourself. You flop your tail both with a sense of nervousness and unfamiliarity with having the appendage.
"To answer what I think must have been your question from before, I've turned you into a horse. I fine looking specimen I might add." the woman says. She unlatches the gate and opens it wide. "Now, let's get you out into the field. You're undoubtedly still feeling quite stimulated and there's a certain young lady I'd love you to meet." she says and pulls a bridle off a hook on the wall. She touches your neck, which relaxes you, allowing her to snap it on. She guides you out to an open, grassy area. It becomes clear what she meant when she told you about the young lady. There she stands in the fenced in area, a white mare. You turn to the sorceress and would glare if your face would allow. She simple smiles again, this time her grin is somehow both mischievous and malicious.
The mare sees you and approaches. As she gets closer you're reminded of how aroused you are, a feeling that only increases as she nears you and you can smell her unfamiliar, but enrapturing smell. The mare touches her check to yours and nuzzles you a bit. She then turns around, her tail lifts slightly to present herself to you. The urge mount her and push yourself deep into her is almost overpowering. You find yourself walking towards her almost unconsciously, but you feel a tug. The sorceress is still holding your bridle. You look at her.
"Now know your punishment." she says sternly "This bestial lust that brought you so brazenly to my room is part of your curse. It will never fade on it's own. This beast before you is your only salvation from it. But should you mount her, spill yourself inside her, than you will be trapped as a horse forever. Not even my magic will be able to save you." she says and releases your bridle. That smile of hers returns.
"Go. Mount her. Surrender to your lust and walk as a horse for all time." she says with a evil tone. You want to. More then anything you've ever wanted in your life, you want this, but if you don't then perhaps she or the cousin she mentioned earlier will change you back. The mare flicks her tail and you catch an even more powerful whiff of her heat.
You must choose...