"Here, hold her mouth open. I'm going to pour some of the 'Human-Female' vial into her. That ought to kill most, if not all, the lust inside her. Her hormones must be going nuts. I'll have to tell Chris about that later." Danny said.
Chris was the other caretaker stationed at the barn. He had gone away to the GenTech HQ for some new supplies, and to share their discoveries. Like Danny, Chris had once been a participant. And after joining the project, he'd signed on as a biology expert, and vet for the subjects who chose animal transformations. Which was why he was positioned at the stable. Everyone who ended up there had some level of animal transformation.
"When will he be back?" Sara asked, bending down to open Mary's snout.
"Probably tomorrow morning." Danny said. He pulled the vial from his lab coat, and poured the contents into Mary's mouth. She coughs a few times, not expecting the liquid to run down her throat. But eventually swallows enough of it.
Her body quickly lost mass, and her animal features melted away. Her arms and legs shrunk, and her hooves split apart giving her real human hands again. Her feet do the same thing, the hooves cracking apart and forming toes. Her tail is sucked back into her ass, which has also lost form and weight.
Her pussy shrinks back into a cute, compact pink slit. Her maleness shrinks as well, until Mary is left with a normal clit. Her testicles fizzle to nothing, she's left with slightly enlarged labia. Her breasts shrink back to their normal size, as do her nipples.
Sara's a little sad to see her new playmate lose her attractive qualities. As sick as that sounds, she really did enjoy the animalistic sex. Once Mary's transformation is over, she's left an average female. Covered in dry bull and horse cum mind you, but normal in all other senses.
A breeze passes through the barn from an open window, and Mary shivers. Sara goes over to her and sits beside the naked human. Danny hands her the same blanket he'd given Mary that first night. Sara wraps it around Mary's shaking form, and then the two leave her.
When Mary wakes up...