When a rainbow appears on the farm, Roy goes after it in search of the legendary pot of gold. He instead gets a dirty sock, which leads him to a game show.
The farm animals are taking shelter during a long rainstorm. Just then it stops and a rainbow appears making Roy excited as he begins running toward it. When Sheldon asks Orson why Roy is so excited, Orson says there is a legend of a pot of gold at the end of the rainbow guarded by a leprechaun.
After a while, Roy gets tired and is about to give up when he sees he is almost there. He races to the end where he sees what looks like a game show hosted by a leprechaun. When he asks where the pot of gold is, the leprechaun, Hymie, informs him that they got rid of it a long time ago, as it clashes with today's currency. He then says that Roy has won a dirty sock, making Roy upset.
Hymie then suggests to trade the sock for something behind the mystery curtain. Roy wastes no time in selecting the curtain, betting the prize will be two dirty socks. The leprechaun asks his unseen helper Johnny to reveal the prize, which is a new car with numerous accessories. While not gold, Roy agrees that it is definitely an upgrade from the dirty sock.
Hymie brings up another offer; keep the car or trade it for Door #2. Taking the risk, Roy accepts the door which reveals to be "Fame and Fortune", complete with fame, riches and everything he wants, much to Roy's excitement. Hymie shows a final offer: he could keep the prizes or trade it for Door #3. Thinking it has more, Roy accepts the door; to his horror, he sees he has re-won the dirty sock. Hymie sympathizes with Roy and thanks him for playing End of the Rainbow as Roy regrets his decision.
Back at the farm, another rainstorm has cleared revealing another rainbow with Orson planning to head to the end. Roy (now wearing the dirty sock) walks back telling him not to waste his time making Orson, Booker, and Sheldon wonder what happened.
Meanwhile a dog has reached the end of the rainbow and Hymie rewards him with a dirty sock. He then notes throughout 73 years of hosting End of the Rainbow, while he has not sold any car or money, he has given away many dirty socks.
- The episode is named after a song from The Wizard of Oz.
- The game show is a parody of Let's Make a Deal.
- The dirty sock acts as the zonk prize (an item of little to no value).
- Johnny's name may be an allusion to Johnny Olson.
- Animal versions of Jack Nicholson and Bill Cosby are shown in Roy's daydream.