A routine physical exam at the Springfield Nuclear Power Plant reveals that safety inspector Homer Simpson has become sterile after being exposed to radiation. Fearing a lawsuit, plant owner Mr. Burns awards Homer with the "First Annual Montgomery Burns Award for Outstanding Achievement in the Field of Excellence" and a US$2,000 prize in exchange for a legal waiver freeing the nuclear plant of all liability. Joe Frazier is the host of the award ceremony, which features extraordinary extravagance in order to trick Homer into believing that it is a real ceremony.
The Simpsons cannot decide on what to do with the money (suggesting an encyclopedia subscription, a new washing machine and dryer and a machine gun), especially Homer, who wishes to buy the Spinemelter 2000; an expensive vibrating chair. Herb, Homer's half-brother, now living on the streets, was the owner of a successful car manufacturer before he was ruined by Homer. After observing a mother unable to discern what her baby wants, Herb comes up with an idea to help regain his wealth: to create a machine that will translate baby babbling into actual English. Upon seeing a newspaper about Homer's award ceremony, he decides to visit Homer. After getting cleaned up by the Flanders family, he requests the money to finance his project, though not before a slight loss of inhibition through punching Homer in the face, as Herb is still mad at him. He builds the translator and presents it at a trade show, which proves to be a huge success.
Along with returning the $2,000 to Homer, Herb buys several gifts for the Simpson family, including a new washer and dryer for Marge, a subscription to the Greater Books of Western Civilization for Lisa, and a lifetime membership to the NRA for Bart (since he is too young to have the machine gun he mentioned earlier). Herb then tells Homer that his gift to him is forgiveness for ruining him in the first place, and he and Homer re-establish a brotherly relationship. Finally, Homer is rewarded for his generosity and faith when Herb has a truck pull in with the "damn chair", the Spinemelter, which Homer is ecstatic to receive. The episode ends with the family relaxing in the living room while Homer happily relaxes on the vibrating chair. The final shot is of Homer's sperm, clearly jiggling, suggesting Homer's sterility may eventually be cured with the massage chair.