When Buffy's lover Angel was shot by Faith with an arrow laced with the Killer of the Dead, a poison specifically for vampires, Buffy needed Slayer's blood in order to cure him. Due to her ongoing opposition towards Faith and her alignment with Mayor Richard Wilkins III, Buffy decided to take Faith's blood by force.
Faith was in her apartment, reading a magizine whilst chewing on some liquerice and listening to music. Buffy then alerts her attention by turning off the stereo sounding the music. An eager Faith responded to Buffy who told her what the cure wass and that she would kill her to get it. Faith gladly agrees to a death match, knowing it would betray Buffy's rule not to kill humans. The two Slayers begin battle and after a minute or so, the fight ended up outside on the roof of another building. Buffy then handcuffed herself to Faith so she doesn't get away. Buffy proceeded to beat Faith as she hung from the handcuff until Faith gained the upper hand and used her superhuman strength to break the chain connecting them. Separated, Faith equiped herself with a steel bar while Buffy took out Faith's knife. After a brief struggle, Faith held onto Buffy by the edge of the building, intending on pushing Buffy off. Buffy then unhanded Faith and pushed the knife into her stomach. A shocked yet satisfied Faith punched an equally shocked Buffy, declaring that even though Buffy may have killed her, she still won't be able to save Angel. Faith then fell onto a passing truck.
The Mayor was informed of the disturbance at Faith's apartment and investigated, reaching the apartment just after fight where Buffy already left. With no other alternative, Buffy made Angel drink her blood. As Angel was cured, he quickly dressed up and took Buffy to Sunnydale Memorial. While Buffy rested in a hospital bed, so was Faith. The Mayor, realizing Buffy was there, attempted to kill her by smothering her face while she was unable to protect herslef before Angel came and shoved him off. Buffy eventually recovered, but Faith was rendered comatose until she awakened the following year.