Isolation ( 隔絶 / かくぜつ / kakuzetsu ) is the sixty-ninth chapter of the Elfen Lied manga series.
Lucy taunts Nana about how she has only her head left to lose and prepares to kill both her and Kurama. The sight of this triggers a sudden reversion in Mariko from her infantile Myu personality, and back to her usual self. However, she now wishes him well and urges her to take care of him, as she rises to confront her target herself. Shirakawa is stunned by this, for not only is this change in Mariko herself but is unheard of among Diclonius children, who often kill their families first.
Mariko asks Kurama right after she kills Lucy, that she promises not to kill anybody anymore, and if he can accept her. While hugging her, he says that they both have a lot to redeem, and they will do it together. As Lucy mockingly taunts this tender moment, Mariko assaults her and sends her smashing through several boardwalk railings. She then easily turns back her furious attempt to counterattack and punches her multiple times with her vectors, which are far superior in number, length, and raw power than her foe's.
The alarm for Mariko's bomb timer goes off, which indicates there are less than five minutes left before they all go off. Mariko and Shirakawa hear this and find the damaged remote right next to Lucy herself, who seems to pick up on its importance. When Shirakawa learns that Isobe is dead, she feels guilt that the bombs will soon put an end to the reunion between father and daughter, with herself being responsible for ordering them to be placed in Mariko's body. She tries to distract Lucy long enough for Mariko to reclaim the remote, but the former obtains it, mercilessly taunts her with it, and tosses it into the ocean. Mariko barely recovers the remote in time but fails to realize that Lucy now has the drop on her. As Nana unsuccessfully tries to shout out a warning, Lucy severs both of her legs.
- As Mariko's fate begins to resolve, she shows up on this chapter's cover looking much like she did in Kurama's dreams of a better life for her, although also as she looked during the story's battles.