Sunnydale has been destroyed and so the scoobies have been on the move until they come to L.A. It is there they meet up with Angel and the Angel Investigations, finding out that there has been a lot more demonic activity.
Willow and Tara are leaders of the Wiccan group, Faith has met up with her cousin Zy after quite a few years of being apart, Buffy is leading the Slayers with Giles leading the Watchers. Xander is training up a few people to help back the Slayers up. Angel is leading Angel Investigations and has the help of Cordelia, Wesley, Fred, Gunn. It's a wild ride in L.A.
Ethan Rayne is back, bringing more chaos and more demons. He has just finished doing a ritual to make him as powerful as a demon god. Looks like his chaos worshiping paid off. He has been killing Slayers so he can rule this world. It's up to Buffy and the gang to stop Ethan Rayne once and for all.