Buffy returns from living in Los Angeles after she killed Angel in season two. Unfortunately her friends and mother are not as pleased to see her after her long absence as she hoped.
At the end of season two, Drucilla killed Kendra, so we are introduced
to brand new Slayer, Faith. Faith is a very confident young woman who
enjoys everything that being a Slayer has to offer.
Xander and Willow finally acknowledge that there is more to their
relationship than platonic feelings, thereby destroying their relationships
with Oz and Cordelia, even though they don't continue the relationship..
As a result of this we are introduced to Anyanka, a vengence demon who will become a bigger part of the gang's collective lives, particularly Xander.
Meanwhile, the Mayor of Sunnydale; Richard Wilkins III, who it turns out is one-hundred year old mortal who sold his soul for eternal life, plots to become the ultimate demon and take over Sunnydale. When Faith accidently kills one of his human lackeys, the experience is so traumatic that she denies all her feelings about the situation and switches sides.
Buffy is forced into a position where she puts Faith into a coma and gets the entire graduatingclass to take down the Mayor during their graduation ceremony.