Paradigm City, a futuristic metropolis, has lost its past. A mysterious occurrence, known only as "The Event", has stolen the memories of the city's denizens and left them under oppressive police rule. While Paradigm City's collective population struggles to remember their past, Roger Smith, a "Negotiator", seems to have a connection to the city's past and sets about investigating this mystery. With the help of the Big O, a crime fighting robot suit, Mr. Smith searches the underbelly of the city for an answer as he tries to uphold his sworn duty to protect the populace.Here, Mr. Smith investigates the mysterious accidents that have been plaguing the city's police force, and many believe the culprit is some sort of ghost. Later, having had enough of Dorothy's lousy piano playing, Mr. Smith takes her to see Instro, a gifted android pianist whose creator is also the bane of Paradigm City.