The griffon was screaming at the fat man outside its cage. The fat man's hands were swollen with scrip. The seller's dark eyes were round with possibility.
Callie slid past them into the market proper, the braided horn warm between her breasts. Hoping the old lady would still be there. Hoping she'd found another unicorn.
Hoping she hadn't.
The old lady had grown older still. Big-knuckled and bent, currying the unicorn's mane. Her smile as naive as ever.
Guilt twisted at Callie's gut.
"Goodmother," she greeted the old lady, a knuckle pressed against her forehead. "To the day."
"Well met, my dear," the goodmother croaked. Her eyes dancing like a girl's. "It's been years."
Callie cocked her head. "You remember?"
"Oh." There wasn't much more to say. "You're not angry?" The guilt had been a candle. Now it grew to a roaring flame. "Why are you not angry?"
"You've brought the horn."
Stunned to silence, Callie slid the twist of ivory from beneath her blouse.
The goodmother smiled as she took it in both hands. She bent her head to kiss it. "The good ones, when when the unicorn dies, the guilt brings them back."
The guilt, Callie thought.
"Only the good ones," the goodmother said. "The secret sisters the Goddess watches over. The ones like you and me."
In the darkness, her belly roiling, Callie crept to where the goodmother slept against the unicorn's flank, the horn cradled in her arms like a dollkin. Callie knelt beside the unicorn. Put her hand on its horn. Moments passed. Callie summoned her will and the spell.
The goodmother opened her eyes. Smiled up at her. "I knew you'd come."
She reached up. Pressed the butt of the horn against Callie's forehead.
The change, when it came, burned like revelation.
The challenge, this one from /r/writingprompts, was to write a 300 word story where the reader thinks they see the twist coming, but the twist is an entire other thing. I was going for the reader thinking they saw her coming back to steal the unicorn. Not sure if that actually qualifies as a twist or not, but there y'go. Whaddya think?