Big O is an action cartoon about a guy who lives in a town where all memories have been forgotten or lost. There are very few elders in this town of which know what happened to cause everyone to lose their memories. The main character of the show is referred to as "Negotiator" and has a butler that is somewhat like Alfred in Batman. The Investigator is similar to Bruce Wayne.
He has a large machine in his cartoon that is referred to as a "Megaduece" that helps him fight crime and other megadueces that pose a threat to other citizens of the town.
The citizens of this town are classified between two things: rich & poor. Rich people envelope themselves in large domes with simulated weather and comfortable living styles while the poor straggle upon the ruins of the city of forgetfulness with everlasting thunder and darkness.
In the series the Negotiator meets up with an android built to protect her master. She was seen by others as a niece to the elder who created her until the Investigator got on the scene. He finds out her secret and recruits her to his staff of one at his dome. There as she becomes comfortable with Roger(the Negotiator) she begins to crack jokes on his way of life. She later learns of Big O, Roger's megaduece and for the first time operates in an episode where Roger and another woman are trapped in underwater ruins.
She states "I am much better suited to operate Big O in the water for the one fact that I don't need oxygen to breathe under water." She saves Roger and the broad.
Roger then leaves to find out just how Big O moves around underground. He digs to find something so crazy that he of all people becomes scared. He wonders to himself how he could lose so much control over his emotion, and how this had never happened.