[T]he “conceptual breakthrough” story, where the characters discover something about the nature of the universe which radically expands their understanding of the world... is a story pattern I like a lot, because ... it lets you dramatize the process of scientific discovery.
[W]ith the good-versus-evil story, it’s very easy to tell a sequel to that story. The world is a good place again until another evil comes along and it’s up to the heroines to defeat this evil again, and they defeat it, and you’re back where you started, and you can tell it over and over again. But in a science fiction story–especially in a conceptual breakthrough story—the sequel... cannot look the same because at the end of the first story, we’re in a completely different place relative to where we started. You can tell a different story as a sequel, but you can’t tell the same story....--