Faith the Vampire Slayer is played by Eliza Dushku (True Lies etc.). Faith came to Sunnydale in Season 3, called as a Slayer after the death of Kendra. From the beginning it was obvious that her methods and attitude to Slaying were different from Buffy's; 'Slaying's what we're built for. If you're not enjoying it, you're doing something wrong.'

Faith's flippant attitude was a front, however - her Watcher had been killed before her eyes by an ancient vampire called Kakistos, from whom Faith had fled in terror. Thinking she had escaped, Faith got a nasty surprise when Kakistos followed her to Sunnydale she was forced to confront him. Heeding Buffy's instructions, Faith did as she was told and didn't die. Kakistos however was dusted by an oversized toothpick.

Faith quickly enamoured herself to the Scooby Gang, and just as speedily fell out of favour as her wild ways that had earned her the name 'Firecracker' in high school were leading Buffy into trouble. This came to a head on the night when, staking vamps on the way to battle a demon called Balthazar, Faith accidentally drove a stake through the chest of Alan Fitch, one of Mayor Wilkins' human minions.

What was going on in Faith's head from that point on is up for speculation. First trying to ignore what had happened, then justify it, then shift the blame for the deed onto Buffy, Faith ended up at offering her services as the Mayor's new right-hand 'man'. Once in his employment (and enjoying the perks that came with it as Wilkins 'adopted' her as his 'daughter') Faith committed several thefts and murders on his orders, which peaked with her shooting Angel with a poisoned arrow. The only cure for this poison was for Angel to drink the blood of a Slayer, so Buffy went to Faith's new apartment, intending to bring her back for Angel to drink. The Slayers fought, and finally Buffy stabbed Faith in the stomach with her own knife. Unfortunately for Buffy, Faith then fell off the balcony into the back of a passing truck and was carried away aparently in a coma.

Faith turned up later in the same hospital as Buffy (who had allowed Angel to drink her own blood and subsequently been taken to medical help) and was declared unlikely to awaken. She did, however, make one final appearance in Buffy's mind, advising her fellow Slayer as to the best way to defeat the Mayor.

Faith made a return from her comatose state in season 4 and proceeded to 'appropriate' Buffy's body. She then proceeded to sleep with Riley (Buffy's current flame) before ending up in a church attempting to defeat a bunch of vampires. By this time, Buffy had a method of returning to her own body rather than Faith's (having been captured by 'The Watchers' Council' for deportation and escaped from them with little difficulty). Faith once again left Sunnydale, this time wide awake and in an empty train carriage.