Paradigm City... A City of Amnesia, where forty years ago everyone lost their memory. But humanity continues to survive. They’ve learned to operate machinery, produce electricity, and go on living from day to day. Still, there is something missing in a town with no past. Roger Smith is a Negotiator. He controls the Megadeus called the Big O. Together with the unusual R. Dorothy Wayneright and Roger's loyal butler Norman, Roger keeps Paradigm City safe from the nightmare of memories.