Another crate washes up in the lagoon, this one seemingly full of an experimental plastic that dries into a very hard form. The Castaways waste no time in making a number of items from the plastic, from a set of golf balls for Mr. Howell to a tooth filling for Gilligan. Unfortunately, a monkey chooses that moment to demonstrate the drawback to the material — once hardened, the plastic becomes violently explosive.
This episode includes examples of the following tropes:
- Black Comedy: While she's trying to remove Ginger's plastic earrings, Mary Anne tells her roommate not to move, or the earrings will pierce her ears the difficult way.
- Distinction Without a Difference: During one of the monkey's explosive-throwing sprees, Mrs. Howell cries for her husband to run. Mr. Howell proudly says that a Howell doesn't run when faced with danger. Then the monkey throws something else, and he adds that a Howell facing danger walks extremely fast.
- Dramatic Irony: The viewer, having seen the opening segment on the mainland, knows that the plastic will explode once it hardens. The Castaways don't. This results in a very tense scene partway through the episode when Mr. Howell keeps being interrupted while trying to tee off with an explosive golf ball.
- Friendship Moment: The Skipper becomes very upset when the Professor explains how dangerous Gilligan's situation is. Later, after Gilligan has startled himself awake and thinks he's blown his head off (he accidentally blew a bubble with the Professor's tree gum mouth guard), the older sailor stays by him, trying to calm him down so he doesn't do anything that could really hurt himself in his panic.
- Hair-Trigger Explosive: The plastic is actually plastic explosive and blows up with a single good shock, which the Castaways unfortunately don't discover until they've already made a number of things with it. Furthermore, one of the island monkeys develops a liking for throwing the explosive materials.
- Nitro Express: A variant; the Professor has unfortunately already used the plastic explosive to plug a hole in Gilligan's teeth when the Castaways find out what it is. The Professor warns the first mate not to do anything that could set it off, including tripping over things. The clumsy Gilligan doesn't find that warning helpful.
- Organ Grinder: After the revelation that the plastic explodes, the Howells are discussing what reward to give the monkey that accidentally cued them in to the danger. Mrs. Howell suggests an organ grinder.
- Stuff Blowing Up: With the Castaways fashioning the explosive plastic into various implements, there's plenty of that.
