About this "The Simpsons" episode: The Simpsons - The Saga of Carl Carlson is the 21st episode of season 24 and number 529 overall in the series.
Bart and Lisa become addicted to a new karate show and they can't live without it until the Family go to a probability museum where Homer becomes fascinated by a lottery video featuring french philosopher Blaise Pascal. Homer, Lenny, Carl and Moe team up and win the Springfield lottery but during an night party, Lenny notices that Carl is missing. As Homer, Lenny and Moe go to Carl's house, they realize he flied with all money. Thanks to Lisa, Homer discovers that Carl flied to Iceland. They arrive and meets a man who tells them about the Carlson's family history. As they manage to catch Carl, they are shocked to learn that the reason why he travelled to Iceland was to clear his family's name and that he did not tell them because he does not consider them as real friends. Angered by this, Homer, Moe and Lenny steal the missing page Carl wanted to have but a call from Marge makes Homer have second thoughts. They learn Islandic language and manage to understand the page signification. Then, they explains to Iceland people what goods deeds Carl made for them (He helped Lenny to move in, helped Moe to paint his windows and gave Homer his last duff beers). Touched by this, Carl apologizes and recounciles with them. Back at Springfield, Carl thanks his friends for having taught them the true values of friendship. After that, Homer is able to pay a new kind of swimming pool for his family though he remains stuck in it.