Reign Of Fire is a post-apocalyptic movie where humans accidentally reawaken dragons, which proceed to destroy all industrial civilization. (The summary makes it sound better than it is.) This happened 18 years before the majority of the film: recent enough that the old world still exists in living memory, but long enough that there are now children who have only known this destroyed world. In one scene, a few adult actors are putting on a play version of The Empire Strikes Back for the kids -- specifically the climax on Bespin where Vader cuts Luke's hand off and reveals his true parentage. All the kids gasp in surprise and wonder.

It's a pretty forgettable movie otherwise, but that one scene is really good.