BOTTLEEPISODE
Bottle episode
In episodic television, the term bottle episode refers to an episode produced inexpensively and restricted in scope to use as few non-regular cast members, effects, and sets as possible. Most bottle episodes are shot on sets already built for other episodes, frequently the main interior sets for a series, and consist largely of dialogue or scenes for which no special preparations are needed.The above text is a snippet from Wikipedia: Bottle episode
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