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I'm case you're wondering:
Chekhov's gun (or Chekhov's rifle; Russian: Чеховское ружьё) is a narrative principle that states that every element in a story must be necessary and irrelevant elements should be removed. For example, if a writer features a gun in a story, there must be a reason for it, such as it being fired some time later in the plot. All elements must eventually come into play at some point in the story. Some authors, such as Hemingway, do not agree with this principle.