The Simpsons: Season 17, Episode 13
The family is on a nature walk through “Carl’s Dad Caverns,” when Homer tries to get a piece from a stalactite. This results in the family falling through the cave floor and winds up with Homer getting stuck in the ceiling of one of the lower chambers of the cave. Marge, Bart and Maggie go off to find help, while Lisa stays behind and tells her father a story to pass the time. Her story involves running from a bighorn sheep and into Mr. Burn’s mansion. The pair evades the tenacious sheep by finding refuge in the mansion’s attic, where Mr. Burns tells her the story of how he came to work at Moe’s Tavern by losing a scavenger hunt with a rich Texan. While there he learned (and tells to Lisa) the tale of the Moe’s treasure. The stories within stories culminate in the fate of the treasure being determined in the cave.