Unable to free herself Abigail's shoulder's slumped in defeat, though they didn't have far to go, her arms ached, the muscles and bones slowly stretching and reshaping, already several inchs longer than they had been only minutes earlier. Before long the young woman's arms would be a match for her legs in their length.
Forcing herself to look down, Abigail retched as she saw the source of the numbness in her hands and feet. Her fingers and toes had begun to fuse, and her nails had darkened as the keratin slowly spread up her fusing digits. With a gulp Abigail realised that soon it would be hooves she was looking down at.
Hearing a beep Abigail looked up, realising that Dr Eliza has pressed another button on the control panel as the side wall retracted into the floor with a whir, revealing another pen. Inside was a huge stallion with jet black hair. The stallion briefly glared at Dr Eliza before training his gaze on Abigail.
"Meet Henry" Dr Eliza proudly declared, "he was my first fully successful species conversion, a perfect blend of thoroughbred race horse and a footballer I 'obtained' from a college near my old lab a few years back". Abigail squirmed as she felt her ears stretching, her eyes briefly meeting Henry's before flicking away in embarassment as she remembered her nudity. As pressure starting to build in her tailbone Abigail moaned, still listening to Dr Eliza's insane monologue.
"This young stud's been without a suitable partner for two years now" Dr Eliza laughed. "I haven't had the resources and a suitable lab to start my project proper until now". "The authorites were growing suspicious of my involvement with all the missing people you see, I had to relocate".
"Ahhhh.. fucccckkkk!!" Abigail interupted as the growing pressure above her rear finally burst, the skin around her tailbone splitting as an equine tail practically shot out, the dark brown hairs hanging down her fattening rear, only partially concealing the darkening flesh of her asshole as it slowly enlarged.
"...'fuck', I'm glad you know the word" Dr Eliza said sharply, annoyed at the interruption, "Because that's what your going to be doing momentarily". "You know how horny young men are Miss Willowsworth, Henry won't be able to resist you soon enough!" Dr Eliza laughed slapping her hand into Abigail's hairy ass as she withdrew from the pen and the fence dividing Abigail and Henry's pens began retracting into the floor.