Gilligan is acting as caddy for Thurston while he plays golf. Currently he is looking for Thurston's ball in the brush. He finds the ball but falls into a deep cave. When Thurston finds Gilligan in the cave he sees something yellow down there with him. When he hears that it's gold he falls into the cave too.
The girls are fishing even though they aren't having very much luck. They keep losing the bait off the hook. But they go catch the life raft from their boat. The Skipper comes to help them reel it in.
Thurston explains to Gilligan how he knows that the yellow stuff on the walls of the cave is gold. Gilligan reminds him that all the castaways made a promise to share everything they find on the island including the gold they just found. Thurston also explains that gold makes people greedy and that they don't want to corrupt the others. He also hires Gilligan and Lovey to mine the gold at night so the others won't find out. Skipper shares the news about the life with the others.
Gilligan and Skipper get to work repairing the raft. Thurston reminds Gilligan about mining for gold that night. Later at night Skipper spends a long time talking but evenutally falls asleep. Gilligan and Thurston work in the mine. Gilligan doesn't get any sleep. The howells put him to bed. The other wonder why Gilligan is so tired, why Thurston is so nice, and why the Howells suddenly don't want to be rescued.
Another night is here and the other castaways follow Gilligan secretly to the mine. Skipper tries to negotiation with Thurston but he won't budge. Everyone but Gilligan has gold fever. Ginger tries to charm Thurston into sharing his gold but it doesn't work. She even tries using reverse psychology.
Everyone starts digging for their own gold. Gilligan, Skipper, Mary Ann, and Ginger are all grumpy because they haven't found any gold. To make themselves feel better they head to work on the raft. In order to get some of their own gold the castaways start to charge for their services; Skipper rents equipment, the girls charge for food, and the professor charges for candles and wicks separately.
The raft is ready to sail. Skipper makes the rule that no one is allowed to bring any gold aboard for fear that it will sink the raft. As they climb into the raft six castaways brings momentos from the island.
Thurston--homemade golf clubs
Lovey--huge bamboo handbag
Mary Ann--box of guava jelly
Ginger--diary of events from the island
But as they head out into the lagoon the raft sinks. Everyone swims to shore. It ends up that everyone's momentos were used to hide gold. All that extra weight sunk the raft. Drying off around the campfire everyone agrees never to be greedy again. This is until Gilligan finds a perfect pearl inside of an oyster. The other six run to the cove to collect oysters. Gilligan shows the four pearls he's found.