Why does maniac invite mars bars to the birthday party and what happened?
Maniac remembered how clueless Grayson was concerning blacks and their home. The McNabs were planning a war against the blacks and had built a pillbox for protection. A military pillbox is a type of bunker (see link for pictures) for protection during an attack. The McNabs thought they were going to be attacked by the black people on the other side of Hector Street. Mars Bar had been one of Maniac's main tormentors because Maniac was white. He called him Jellyfish. Whites never go into the black houses and do not know black people, and blacks did not know about white people. So he decided to bring Mars Bar to the white party of the McNabs. The father, John McNabb, challenged Mars presence and then stormed out the room telling everyone to let him know when "it" (Mars Bar) left. Then the kids started playing a game in the pillbox of blacks vs. whites. As they were arguing about it, one of the Cobras jumped down from the hole in the ceiling, barely missing Mars Bar. Maniac had to restrain Mars, and then escorted him to the other side of Hector Street. Maniac had to admire Mars Bar though because he had been very scared, but he didn't show it.
Maniac invites Mars Bar to the birthday party in order to teach him about white people. He also wants to educate white people about black people because he realizes that discrimination is rampant in Two Mills. Maniac learned that the McNabs had built a fortress of sorts in order to protect them from black people. They called it the "pillbox," and Maniac presumably wished to change their prejudiced minds.
Mars Bar is a bully who calls Maniac "fishbelly" and other names in order to show dominance over Maniac. He is tough, arrogant, and brave. However, when he shows up at the McNabs' house for the birthday party, he quickly changes. He is uncomfortable in a white home, and the McNab family is just as uncomfortable with him. A fight nearly breaks out between Mars Bar and John McNab. Maniac steps in and escorts Mars Bar from the home. This is a turning point in the novel.