Faith, Hope & Trick 
Story Line
The next day, Faith is given the grand tour of Sunnydale High. Although Buffy's friends (bar Cordelia) and Giles are completely won over by the 'zesty' Slayer, Buffy is not. In fact, she's jealous. She is far from impressed with her new nickname 'B'. Not to mention that Faith seems to be getting on better with her "Non boyfriend. . ." (Scott) than she is!
It takes Willow to silently gesture to her friend to invite Faith back to her house for dinner. Reluctantly, she does so. Much to Buffy's annoyance, her mother likes Faith too. However, Joyce's motives are selfish. She wants Faith to take over for Buffy so Buffy can go to college.
This part is important. Despite the fact that the producers/writers were a little lost at the beginning, this part of the arc remains. It's automatically assumed that Faith is just a Slayer and pretty much has no life per se. Again, it's very important as friends and a sense of belonging are what Faith is desperate for, although she'll never admit it.
After dinner, both girls patrol and fall across vampires. Again we see an important part of the Faith story arc. Faith doesn't merely quip and slay, she thrives on pummeling a vampire while leaving a fairly annoyed, if not frightened, Buffy to slay the remaining vampires and pull Faith off the one she's beating to death, then slay that one too. Buffy, after calling Faith for "living large" on one vampire, figures something's not quite right in the state of Denmark. Further investigation reveals that Kakistos and Faith have encountered each other before. Kakistos murdered ( "There are no words for what he did to her" ) Faith's Watcher and Faith has come to Sunnydale for Buffy's help (although, again, she wouldn't admit it.)
Eventually, both Faith and Buffy are driven to Kakistos' lair where Faith freaks. Buffy calms her, but the arrival of the vampires leaves Faith almost paralyzed. It's not until she sees Buffy in major trouble, that she snaps out of her fear and finally slays Kakistos. All the while Mr. Trick looks on doing nothing. He believes the vengeance crusades are out of style and flees. After contacting the Council Of Watchers, Giles informs the girls that they have approved Faith staying on until her new Watcher arrives. Faith fans rejoice!