The Secret of Gilligan's Island

The Secret Of Gilligan's Island is the 93rd episode of Gilligan's Island and the 25th episode of the Third Season. It aired on March 13, 1967.

Synopsis
Looking for Gilligan, the Skipper finds him in a cave he told him to stay out of, but they find what look like a very old Stone Tablet with hieroglyphics on it. Checking it out, the Professor thinks it gives clues on how to leave the Island. Unfortunately, the greater segments of it are missing and he sends the other Castaways to search the other caves for more fragments. The Howells find a segment by chance in one cave chamber, while the girls discover another stone tablet while fleeing from a bat. The Professor meanwhile has Mary Ann cook some acid to burn the dirt off the tablets; she just barely saves Gilligan from drinking it when she steps away. Eventually, the Professor restores enough of the tablet to understand it, but he finds he is still missing one piece. When he describes it as the same size and consistency as a flat rock Gilligan has been using as a tray, it dawns on everyone that Gilligan has had the missing piece the whole time. In his excitement, Gilligan accidentally drops it and shatters it, but the Professor finds the fragments large enough to restore for the final clue. Reading the directions regarding time and ocean currents, he believes Gilligan and the Skipper should finally be able to sail for help. The night before they set off, Gilligan has a dream of life during the Stone age. He sees himself and the Skipper wanting to move to a new land, and Mr. Howell as the angry chief trying to stop them from leaving. He even tries imprisoning them in the dream, but Ginger rescues them. However, upon making the journey, they discover their new land guarded by a huge dinosaur and Gilligan wakes from the shock. The Skipper calms him from the terrifying dream just as the Professor arrives and cancels the trip. It seems he read the hieroglyphics backward, and they actually explain how the island's original prehistoric inhabitants got there. Later that day, Gilligan carves his own tablet for future castaways; it reads, "Home Sweet Home."

Credits
Main Cast
 * Bob Denver as Gilligan
 * Alan Hale Jr. as The Skipper
 * Jim Backus as Mr. Howell
 * Natalie Schafer as Mrs. Howell
 * Tina Louise as Ginger
 * Dawn Wells as Mary Ann
 * Russell Johnson as The Professor

Guest Cast
 * None

Trivia

 * Syndicated versions of the episode omit the tag scene with Gilligan showing off his own hieroglyph.
 * The footage of the allosaurus comes from the 1960 movie, "Dinosaurus."
 * The cave the hieroglyphs come from looks like the same cave as the native relics in Voodoo Something to Me.
 * Mary Ann and Ginger are menaced by a fruit bat, first seen in Up At Bat.
 * The close-up of the tablet Gilligan has been carrying shows pineapples and bananas, known staples of the Castaways, as well as apples and something that looks like squash.
 * The Professor uses the words "demotically" and "boustrophedon" incorrectly. He uses them to describe the differences from reading left-to-right or right-to-left, but "demotically" actually refers to anything belong to a group of people while "boustrophedon" refers to writing in alternate lines in opposite directions (as from left to right and from right to left).

Quotes

 * Gilligan - Chief Howell say we stay here for 100 years or until we die... which ever come first.