Edit: if it helps I did remember that it is on the authors site(no I don't remember who) and there is another unfinished fic there that I think may be a crossover? with aliens coming and Willow goes see-through to spy on them or is captured and goes see-through to communicate with the rest of the gang?
Edit2: In my original post the story I am looking for has only one cat, a grown cat. Not kittens. But I'm not saying to stop sending me kitten fics 'cause yeah sooooo cute. Thanks!
Edit: Vicious strays by Kiara.
But um... you can keep the kitty stories coming...if you want.