So. Never written Rayne before. I'm not even sure if this actually counts as Rayne. Tell me if it's any good?

She picked it up on some border planet they stopped at.
One minute she was there, the next she was avidly watching as the stooped over
old woman turned bits of paper into birds with a flurry of her hands.

River was fascinated, and within minutes had a small bird perched in
her fingers. After that, her hands never stopped moving. Any little
bits of paper left alone were subject to her new hobby.
A few of them found their way into different places-a grease stained page from a
manual became Kaylee's new favorite toy, and a torn page from a
storybook was proudly displayed by Wash on the controls.

But most of them disappeared, and no one knew where they got to.
Until the day Jayne poked his head into her bunk. Gorram girl was bein' creepily quiet, and that could never mean anything good.

He was met with a whirl of colors and softly rustling paper. It looked like she'd just
stuck them on the walls and ceiling at random, whenever she was
finished with one. Some hung on strings, dipping and spinning crazily
as they caught the stream of air from the vents. Others were simply
plastered to the wall, creating a mash of colors and pictures that was overwhelming.

Noting his presence, she finished the one in her hands, hung it on a
string, and sent it spinning with a push of her finger. "Shhh." she
whispered, grinning at him. "They're dancing."

Jayne didn't quite know how it happened, but now he had a piece of
paper crammed into his hands and dainty fingers were fluttering over
his, correcting his mistakes and directing the folds. She laughed as
he held up a mangled looking bird, tail bent and wings creased, and
for just a moment, she wasn't the crazy girl with ghosts in her eyes,
and as he hung the badly made trinket next to one made from a ice
planet wrapper, he noticed that next to all the others, the lines and
crinkled parts on it faded as it blended into the dance of paper.

And there was prob'ly some big important anology there, but Jayne Cobb had
never been one to think on things like that.