A month before reaching adulthood, a young girl is given a terrible diagnosis. A year later, having undergone chemotherapy and a bone marrow transplant, she returns home. Diana's parents sell their house, and with the help of an intermediary on the black market, they acquire immortality for their daughter - vampire blood. When the family moves to the port ghetto, Diana begins to lead a reclusive life, becoming depressed due to constant feelings of guilt. She goes out after midnight to buy a standard weight maintenance meal and a bottle of water. On one of these nights, the girl witnesses a crime and helps the seller fight off the robber. Having received a charge of motivation from what happened, Diana decides to become useful to the area and punish criminals.