As she walked toward the sound of shuffling feet and ruffling clothes, Amy noticed out of the corner of her eye that there were a number of footprints painted on the floor. She stopped to examine them more closely. They didn't look like any real creature, but a mix of human and animal. She followed the tracks to see where they led, but they simply went in a straight line. What was odd, however, was that the tracks became more animalistic as they went along, ending in perfect hoofprints. Amy ran back down the tracks, and saw that the very beginning prints were normal footprints.
She looked around for a sign, anything to explain the purpose of these tracks, but found nothing. Her tail flicked in amusement, and she shrugged to herself. She placed her feet on the first two footprints and carefully followed the tracks, putting her feet exactly where the tracks were painted onto the wood floor.
After a few steps, her feet began to itch. A few more steps and they were positively aching. Careful not to leave the trail, Amy slid off one shoe, then the other, placing the feet back on the prints they had stopped on. Her socks looked freakishly swollen, and Amy removed them as well to receive a pleasant surprise. Small hairs were growing on her feet, which themselves looked longer, and her toes looked oddly misshapen. Given her previous experiences, though, Amy knew exactly what this meant.
With socks stuffed in shoes and shoes firmly in hand, Amy proceeded down the trail, watching her feet intently. Each time they landed on a new footprint, her feet shifted ever so slightly to exactly match it. Her middle toes thickened and the nails grew wider, thicker, and darker. Her biggest and smallest toes on either foot shrank and migrated up her feet. Her feet lengthened further, stretching pleasantly a few inches longer, and it became difficult for Amy to properly balance.
She noticed now a brass railing that was set up on the wall side of the tracks, likely to assist people with this very problem. As she continued, the ends of her feet started clacking against the floor, as her remaining toes started to merge and go numb. Amy could feel this change rather than see it, but since the sensation of touching the floor was becoming more and more dull at the bulky ends of her feet, she could only assume that was the explanation.
Eventually, the heels of the footprints disappeared. Amy had to resort to standing on what remained of her toes and the balls of her feet while keeping her heels in the air. She continued on until the new stance became so natural she no longer needed the railing for balance. The footprints were glorified hoofprints now, and the cream-colored fur had grown thick over her new equine hooves. Amy stood on the final two hoofprints with a bright smile on her face. Looking around she noticed she was a good bit taller due to their new shape.
She skipped along on her new unguligrade legs, making loud clopping sounds as she did so, continuing toward the aisle where she heard someone moving around. Through her pants, she could feel that fur had grown all the way up above her knees, but this unexpected development didn't bother her in the least.