Marcia's mind was on overload as she worked the ignorant pony stallion ever so close to her car. As her inner passion tried to work the locking mechanism her stallion partner was so horny he tried to mount the trunk of her car.
With a huge kerthunk' his forehoofs came to rest on the trunk lid of her compacr car. The cheap wagon is was, his weight sprung the lid and lock went in different directions. Working her mind over male pony brain matter she got the dumb animal to plant it's forehoofs inside the trunk. A quick pawing of the satchle popped it open.
There rolled out the cannister of blessed counterspell dust. An additional strain and the pony pwaed the can to burst and spill the silvered dust into the open trunk's floor. As she strained to make her stallion think of sex she felt her body lengthen. Soon erect and bouncing off his belly in the momment of masterbated passion, a little timing was needed.
As her cock body rose to bonk the hairy belly her stallion lower his head and with a sexual snort blew the couterspell dust into the air.
Marcia would have smiled if her cock face had a mouth. The silver dust rose quickly into the air covering not only Marcia's black self but her stallion partner too.
Like being at the grounding point of a lightning bolt the flash of power jolted both stallion and Marcia. As the shock drained from her she open both eyes to see her body. Again she was human, but naked to the world, clothes she must find some clothes.