Disclaimer: None of the characters except Seraphima belong to me.
It had been three months since Sunnydale fell into a crater. Spike had been killed in the final battle while wielding the amulet, and Angel had disappeared from the world. All alone, Buffy Summers and Faith Lehane left the now destroyed Sunnydale towards the city of Santa Clara where they were recieving a calling. Another Slayer, Seraphima Davidson, who had been a slayer for 9 1/2 years previous and was immortal was already there.
The watchers council thought her dead and had been content to let her be. That was until, they discovered that the First Evil had returned and was below Santa Clara. Sera was contacted and agreed to work with the other slayers.
Unbeknowest to the Council, Seraphima was the mate of the local Vampire leader: David.