In season 5 when Buffy scarificed her life to save Dawn. Buffy was dead in the end of season 5. Season 6 Buffy was brought back to life from Willow and the gang. Buffy was lost. She was in terrible pain. The pain would never stop . She wish that it would end. Buffy went to Spike to explain the pain and torment that she felt . She struggles to readjust her life. In the end of "Once plus With Feeling". We all saw that Buffy kissed Spike. Then in "Tabula Rasa". Finally the epsiode "Smashed" she figure out that Spike's chip stop working only on her. Buffy fought Spike in the end of "Smashed" . Then Buffy and Spike stopped fighting . Buffy wants feel something from Spike. The epsiode "Wrecked" Buffy can't believe what happened the other night with Spike. Buffy realizes she must give up her additive relationship with Spike. That it torments her as much as it brings her fleeting comfort.Buffy fears that the magic that brought her back has somehow changed her.