Synopsis by Mark Deming
Homer Simpson (voice of Dan Castellaneta) has gone through life as an only child, but when his father Abe Simpson (also voiced by Castellaneta) has a brush with death, Abe makes a startling confession -- many years ago, he fathered another son during a brief fling with a carnival dancer. Homer is determined to meet his half-brother, and tracks him down to Detroit, where he discovers Herb Powell (voice of Danny De Vito) is the founder of a major automobile company. Herb is thrilled to meet his half-brother, and is happy to play doting uncle to Bart (voice of Nancy Cartwright) and Lisa (voice of Yeardley Smith), while Homer is overjoyed to be staying in a mansion where the kitchen staff is willing to make him pork chops any time of the day or night. Things are not going well at Herb's firm, and he believes they need to design a new car that will appeal to the common working man; since working men don't come much more common than Homer, Herb puts him in charge of the project. "Oh, Brother, Where Art Thou?" (a title that, like the similarly titled Coen brothers' film that was released almost a decade later, refers to the classic Preston Sturges comedy Sullivan's Travels) was first broadcast on February 21, 1991.