Throughout the centuries, an obscure, self-righteous and paranoid vampire sect, the Kien-Jus, venerated a single bone from the body of a deceased Slayer, and used it to protect them from future Slayers. Obtaining the Slayer relic from Tijuana, the nafarious alchemist and plastic surgeon Doctor Flitter working for the vampire Selke used the bone to summon a Dark Slayer to kill Buffy the Vampire Slayer. The spell encompassed the Slayer bone, vampire blood and a polaroid of Buffy. After two unsuccessful attempts, Flitter's spell successfully created the Dark Slayer, an exact replicate of the real Buffy Anne Summers.The Dark Slayer attacked Buffy during one of her nightly jogs, and used Buffy's unpreparedness to her advantage and seemingly killed her, and dumped the body in the sewers. The Dark Slayer then took on Buffy's guise to hurt and kill Buffy's friends, but found out that the real Buffy was still alive.Tracking Buffy down in the sewers, she confronted her 'sister' for a rematch. The Dark Slayer nearly gained the upper hand, but the interference of the failed creation of the Dark Slayer gave Buffy the advantage she needed to send both Dark Slayers into the sewer river for a permanent swim.