Spuffy, Angel S5, Thing of Evil

I am searching for a fic I read once, the premise is that Buffy finds out that Spike is still alive and shows up at WR&H. Angel, in a bid to separate them, creates a fake prophecy about a "Thing of Doom." I remember that Riley and the Initiative were hired by Angel to drop off a random demon in the desert and that Angel burns an old scroll in order to pretend that it was some recently-found prophecy.

It's Thin of Doom by Sunalso.