GAH!!!

I had this GREAT idea wile trying to pick a crossbigbang fic idea, and I LOVE the idea because it's so delisciously AU, but... I don't know how to make it into a crossover... lol...

The basic premise is that Dawn isn't so much an alchoholic junkie as she is mentally unstable. Years ago, one of her boyfriends beat Trey so bad he wound up hospitalized, and when Dawn went to see him she was told he was 'gone', which she took to mean he'd died, and she took off, grabbing Ryan and disappearing by committing a little identity theft (yeah, Dawn's a little smarter as well as being crazy... lol)
( Cut for rambling... )

It's driving me crazy that I can't figure out a good crossover fic to use for crossbigbang... grrr...