In the distant future, on a terraformed Mars, the episode takes us into a cosmopolitan world where humans and androids, known as "Neans," coexist. The story unfolds in a nightclub where the elegant singer Sarah Fitzgerald performs, while the less glamorous but lovable Rouge, a club employee, carries out her duties.

Over the course of the episode, it is revealed that Rouge is not an ordinary human but a highly advanced Nean who can pass as one. This revelation occurs when Rouge injects herself with nectar after her shift, a substance essential for the functioning of Neans. Her advanced design draws parallels to the replicants in Blade Runner.

Rouge's supporter and caretaker, Naomi Orthmann, maintains contact with Rouge through a robotic bird. However, after the bird is destroyed, Naomi meets Rouge in person. Naomi's human status contrasts with Sarah, who later turns out to be another advanced Nean. Sarah's true nature comes to light when she is attacked by a robot known as the "Red Gladiator," which is also involved in various murders.

Meanwhile, a figure named Jeron, notable for his theatrical demeanor and Lennon-style glasses, is on the hunt for a large shipment of nectar. His past connection to Sarah is hinted at when she warns him in a confessional booth that Rouge might be a spy with ulterior motives. Following this, Sarah and Rouge meet privately.

The tension escalates when Rouge, preparing for a confrontation, is attacked by the Red Gladiator. Surprisingly, Rouge transforms into the same Red Gladiator form, revealing it as her combat configuration. It is also disclosed that Jeron can mimic the forms of other Neans. Amidst this, Sarah unveils her true identity as Purgatory Viola and her battle mode, leading to a robotic showdown.

Rouge triumphs in this battle, and Naomi rewards her with a chocolate bar, her favorite treat. The episode ends with the revelation that Sarah and Jeron belong to the "Immortal Nine," a group of elite Neans not bound by Asimov's laws and capable of harming humans. Rouge and Naomi's mission is to eliminate these Nine, marking the end of one and the pursuit of the remaining eight.