Jon just had time to register that the person behind him was Ms Fry the School Librarian before she changed.
Up until this point, Jon realised, he'd never looked straight at someone as they where altered, it had seemed to be instantaneous, but with the sudden unexpected boost in adrenaline to his system sharpening his perceptions, Jon actually got to watch the process, and it was fascinating.
Ms Fry was dressed conservatively, but well in a light jumper, and plain grey slacks, her brown hair in a well shampooed and maintained bob; Jon watched first as her hair lost it's glossy shine and became somewhat more brittle looking before growing out past her shoulder, then shooting back up and becoming a tight bun on the top of her head, all in one smooth motion.
Her face become slightly longer, and her two front teeth seemed to swell in size, while at the same time she developed a slight overbite, giving her face a horsy appearance. Her lips got thicker and smeared with greasy looking, very dark red lipstick, while the skin around her mouth became pinched, making her look liked she'd sucked on a lemon; her nose got slightly bigger, taking it out of proportion with the rest of her face, and suddenly a pair of thick, black framed, catseye glasses appeared on her face, a pearl "hold chain" suddenly looping round the back of her neck.
Her cloths wreathed around her body, her slacks becoming a sensible grey wool skirt that came all the way done to her ankles, and her jumper became a pearl grey blouse with ruffled cuffs and subdued lace at the throat, next and lastly she actually raised up slight as her sensible black flats became a pair of dull brown "granny boots" with a broad four inch heels.
Looking down at her self in shocked horror, Ms Fry looked back up and gave Jon a gorgon stare through her new glasses "What her you DONE to me!?" she demeaned in a shrike that held an undeniably stringent whine beneath.
Backing away nervously Jon stuttered "D-don't worry Ms Fry ev-erything will be f-fine " silently prying that the mental changes would kick in quickly and that afterward the suddenly harridan like Librarian wouldn't still want to kill him.