The navy plans to test a new warhead, labeled operation Powderkeg, on a small island in the south seas, one they're confident has no inhabitants. The Casatways fearfully anticipate the missile's arrival, unaware that a last-minute change in plans means that it has no explosive inside it.
This episode includes examples of the following tropes:
- Big "NO!": The Skipper yells "No!" when the missile takes off while Gilligan is inside it.
- Chekhov's Gun: Subverted. The Professor is making a mirror for Mrs. Howell early in the episode, and he realizes he can use it to signal the scout plane the army will send before the missile. However, the mirror gets broken and the plane never sees the Castaways trying to signal with the pieces.
- Dissonant Serenity: The Professor is the calmest of the group when it looks as though their signal attempt has failed and they're all going to die when the missile hits. One of the others even comments that his remark about its impending arrival sounds like he's waiting for a train rather than an explosive.
- Dramatic Irony: The viewer sees a shot of the mainland where the army men agree to make the test without the explosive part of the missile after something goes wrong with that part. The Castaways never find out that the missile is nothing but a guiding system and they're in no danger.
- "Eureka!" Moment: As the Professor is reminiscing with Ginger about potential regrets, he mentions a past study he was part of about attention effects on pilots...and realizes how he can get them rescued.
- Legacy Vessel Naming: A variant; after it seems like Gilligan didn't escape from the missile when it took off again, the Skipper tearfully says that he's going to call his next ship the Gilligan.
- Match Cut: The army men drawing an x on the map cuts to the Skipper making an x in the sand.
- Pie in the Face: The Skipper keeps insisting that Gilligan take one of his pies and then Gilligan accidentally puts his hand in the wrong place and shoves the pie into the Skipper's face. The Skipper pies him with the other.
- Through His Stomach: When Mary Ann is reconsidering her life after the news, she makes Gilligan and the Skipper each two pies to make up for not being as nice as she feels she should have. Both of them insist she has nothing to worry about, but they're happy to have the pies. Then the Skipper insists Gilligan take one of his to make up for his constant yelling at him...after Gilligan has already eaten two.
- Unwitting Instigator of Doom: The navy decides not to announce the change in plans after they strike the (suddenly faulty) explosive from the missile, not knowing the problems that would cause on the island.
- Vine Swing: Gilligan swings down from the roof of the hut and breaks the mirror.
- Why Are You Looking at Me Like That?: The Professor announces that someone will have to crawl into the missile and disconnect the wire, and there's only one person small and thin enough. Gilligan wonders who that is and realizes that everybody's eyes are on him.
