In 2046, faith in robots has waned, resulting in a decline in their usage. The latest gen of robots, dubbed 'seconds', are in jeopardy. Following the death of his partner by a robot, Ross Sylibus operates as a detective on Earth, an unfriendly hunting ground. To evade the danger, he reassigns himself to Mars. Unfortunately, his plans for a secure environment don't come into fruition. Instead, he's thrown into a homicide investigation of a singer he meets during his voyage. Sylibus and rough around the edges cop Armitage partner up to tackle a surge of murder cases regarding females. Their efforts lead them to the discovery of a concealed troop of robots called "Thirds," who face identical menaces. With the murderer now targeting the Thirds, Armitage reveals herself to be one of them and is driven to find the killer and serve justice.