On a hot day at school, Bart fakes an absence note and skips class. Principal Skinner is suspicious and tracks down Bart in town. Bart manages to escape into the back of Freddy Quimby's car (Mayor Quimby's nephew). He ends up at Freddy's birthday party.
At dinner, Freddy has an argument with the waiter over how to pronounce "chowder." Later, the waiter is brutally beaten in the kitchen, and Bart, hiding under a table witnesses the assault.
Freddy Quimby is charged with beating the waiter, and Homer is on the jury. Bart confesses to Lisa that Freddy Quimby is innocent, but can't tell anyone because Skinner will know he skipped school.
In court, everything is going well for Freddy until the chowder argument resurfaces. Everyone on the jury now believe him guilty. Homer, however, votes innocent so that he can stay in a luxury hotel for free.
Eventually, Bart confesses that he saw the whole incident: the waiter simply slipped and injured himself in the kitchen. Freddy Quimby is innocent, and since Bart showed bravery by coming forward, Skinner gives him just four months detention.