After attending a Spinal Tap concert, Bart announces that he wants to be a Heavy Metal rocker. Homer and Marge encourage Bart to follow his musical dream by buying him a guitar. However, no matter how hard Bart practices, he cannot master the instrument.

Bart brings his guitar on the school bus. Otto stops the bus to play some music. Realizing he is late, Otto races to school, crashing the bus in the process. When Principalo Skinner discovers that Otto doesn't have a drivers license, he suspends him. At the DMV, Otto takes his test to get his job back, but fails when he asks Patty if she has always been a female.

Out of a job and money, Otto is kicked out of his apartment. Bart tells him he can live in the Simpsons' garage. Otto is comfortable, but Homer cannot put up with him and orders him to leave. Marge suggests Otto take the driver's license test over again, but it is only when Homer insults him that Otto decides to get his license so that he can staple it to Homer's head. Patty finds out that Otto dislikes Homer and makes sure he passes the exam.