Cousin Casey welcomes the mice to the first world series of baseball. Casey introduces them to his friend Joey, whose father is the team's pitcher Fast Ball McFall. But there's bad news: Fast Ball is in a slump. Fast Ball assures his son he'll pull out of it, especially since he has his lucky four leaf clover. Unfortunately, the manager for the opposing team knows that Fast Ball is very superstitious, so he makes sure the pitcher's lucky piece disappears. Meanwhile, the mouse world series between the Mudville Rats and the No Sox Mice is heating up while a particularly shifty looking rat keeps stealing the bases (literally!) It's that nefarious Notail Nogoodnik out to win at any cost and it's up to our mice to return Fast Ball's lucky piece and win the game for the No Sox Mice in the bottom of the ninth!