The robot who first rebelled against humans is designated as "BI-66ER," a reference to Bigger Thomas, the protagonist of the 1939 novel Native Son, giving the rise of the machines a backdrop in historical race relations. In the novel, Thomas is a black teenager who comes from a poor, working-class upbringing and goes to work as a butler for an affluent white family until he accidentally murders his employers' daughter and ultimately receives a life sentence for his crimes.