Mother raises the girl, known as Daughter, but shields her from all knowledge of the outside world.
Mother has been programmed to save humanity but she will also kill humans if it benefits her larger plan. Daughter realizes that Mother has been lying to her when a stranger break through the protective barrier.
The stranger, played by Hilary Swank, looks a lot like a much older version of herself. The stranger is injured and distrustful of droids, including Mother. She claims to be in contact with other humans.
After the stranger is better, Daughter takes off with the stranger. She has learned some terrible truths about Mother and the family of embryos kept in the clear cases.
The stranger has secrets, too, which leads the daughter to reject her and return to Mother.
Ostensibly, Daughter has returned for her infant brother and the other embryos. She confronts rather than reconciles with Mother, who is it turns out, is more than a single bot.
In the end, viewers hear Mother's chilling lullaby. Mother is
capable of killing but so too are all the other players in this narrative.
