When Grace awoke she knew something was very wrong, her whole body felt like it was burning, her skin itched and her clothes felt tight against her body. As her eyes fluttered open she remember what had happened, she didn't know how long she had been out but the serum was clearly doing something to her.
As she staggered to her feet Grace looked down and gasped at her bloated body, as she watched fine black hairs were beginning to grow all over her skin, as she screamed in horror her transformation began to pick up pace, her body bloating and contorting. With Holly away today there was no one to hear Grace's scream, she was helpless.
Collapsing to all fours Grace moaned as her torso stretched and lengthed, her body thickening and growing. Her already tight clothes stood no chance as they ripped and fell to the floor. Her arms twisted and locked into a forward postion as they morphed into legs, her fingernails hardening as they encased her hands, transforming them into hooves. Not being left behind her legs also began to swell and change.
Despite the horror of her situation Grace was becoming increasingly aroused by what was happening to her, her once closeted attraction to bulls was forcing its way to the surface as she became more and more bovine. As her legs and feet finished morphing to match what were once her arms and hands Grace was forever locked into a quadrepedal stance.
To better suit her new body Grace's asshole and vagina shifted up her crotch, now fully exposed and facing backwards, as they did they pulsed and expanded, within moments Grace's once petite pink lips darkened to black, becoming thick and leathery, juices oozed from her entrance as her vagina deepened into her torso, now able to accomodate a bull.
Distracted as she had been by her vagina's change Grace became all too aware that her breasts were now between her legs, dripping milk they merged and expanded, two extra nipples forming on the jiggling mass that had been her boobs, with a spurt her two new teats also began to leak milk. She had a udder now.
As a tail erupted from above her winking asshole, Grace felt her neck thicken and stretch, her body was now completely covered in shiny black fur, her time as a human was at an end. As Grace began to moo her head enlarged and her face stretched forward, as her horns finished growing her ears enlarged and her now huge tongue hung from her mouth. Within the space of only two minutes Grace had been transformed into a cow.
Though Grace retained her human mind her inhibitions were gone, if she was going to be a cow she may as well live out her fantasies, as her now huge nostrils flared she could smell the scent of their bull outside, it was about to be his lucky day.