Fringe:

[rainer76]

A little while back there was a standard 'body-swap' prompt written on the kink-meme that I answered hastily if not with any real length  - whereupon a little elf crept inside, grabbed the nearest chair by the fire, charmed all the ferocious, ferocious golden retrievers and extended the story into a sexy tale to make the adults quiver with excitement.  Elfin's just posted the story in its entirety at AO3, and I'm running out of ways to thank her.

http://archiveofourown.org/works/223247