Paradigm City. A City of Amnesia. Forty years ago everyone lost their memory... But humanity continues to survive. They've learned to operate machinery, produce electricity, and go on living each day at a time. Still, there's something missing in a town with no past, no history of what has come before. Roger Smith is a Negotiator, hired to negotiate disputes between parties. And Roger enjoys a reputation of being the best at his job. But he has an ace up his sleeve... a rather big ace. He controls the Megadeus called the Big O, a wondrous piece of technology from before the age of Amnesia. Occasionally, fragments of memories appear, and with them often comes trouble. The Big O comes in handy for subduing such dangers, but does it serve some greater purpose? Together with the unusual R. Dorothy Wayneright and his loyal butler Norman, Roger Smith keeps Paradigm City safe from the nightmare of memories.