The Skipper worries that something is going to happen to him, so he begins to train Gilligan to be a leader. The Skipper then disappears leaving Gilligan in charge, with predictable results!

The Castaways hear on the radio that Mary Ann's boyfriend in Kansas is getting married. Mary Ann overhears the others talking about her, and mistakenly believes that she has been poisoned by the mushrooms she recently ate, and has only a short while left to live. A hilarious dream sequence follows, featuring the Professor sounding a lot like Cary Grant.

Gilligan discovers an island bush that produces seeds which, when eaten, give a person the ability to read the minds of others. This leads to disaster when everyone insults each other through their honesty and thoughts.

An experimental robot launched by the Air Force parachutes onto the island. The professor reprograms the robot to walk to Hawaii ("one hundred eleven hours"), but the "lucky" rabbit's foot that Gilligan secretly stuffed into the robot causes it to malfunction upon arrival in Hawaii.

The Castaways begin to suffer from 'island madness' due to the isolation. The Professor attempts to come up with a plan to lift everyone's spirits.

A cage containing a lion washes ashore in the lagoon. After Gilligan removes a thorn from his paw, the two become pals. When the Castaways run out of food, however, Gilligan thinks the lion has consumed the Skipper.

A ghost appears on the island and tries to scare the Castaways off. The castaways turn the tables by dressing in sheets and roaming around the island to scare the visitors off the island.

Gilligan finds a crate of radioactive vegetable seeds. The plants grow quickly and grossly misshapen, but the Castaways are so hungry for new items in their diet that they consume them quickly. The plants, when eaten, give the castaways super-human powers. Of course, after he realizes that the vegetables are radioactive, the Professor saves the day by making a homemade soup to absorb the radioactivity.

Lord Beasley Waterford, a famous butterfly collector, lands on the island searching for the world's rarest butterfly, the pussycat swallowtail. While he vows that he will not leave the island until he has found his prey, the castaways eagerly try everything to persuade him to fire his flare gun early. He (like all of the other visitors to the island) leaves without sending help.

While fishing, Gilligan and the Skipper reel in a briefcase, stamped with the words ""Property of the U.S. Government."" Everyone believes that the case contains top secret government material. Gilligan accidentally handcuffs the briefcase to his wrist, and has a wild dream about secret agents, evil enemy spies, and deadly spy games!

Famous big-game hunter Jonathan Kincaid and his assistant, Ramoo land on the island in search of new game to hunt. Since they have hunted just about every kind of animal on earth, they then decide that the ultimate challenge would be to hunt a human. After much debate, they choose Gilligan as their target, and state that if Gilligan can stay alive for 24 hours, they will rescue the castaways. After Gilligan manages to outwit and outrun the armed hunters for 24 hours, Kincaid does not uphold his promise of rescue for fear they will report him to the authorities.