Although Star Trek has a long history of exploring the multiverse, I’d still say it’s one of the franchise’s lesser-used sci-fi tropes. That being said, there is a relatively healthy tally of Star Trek episodes that either acknowledge or are set within realities other than the Prime Timeline. Perhaps the most formative is The Original Series‘ “Mirror, Mirror,” which introduced the Mirror Universe in 1967. However, it wouldn’t be until 1993 that The Next Generation‘s “Parallels” would push the envelope further than ever before with Star Trek‘s multiverse efforts. 32 years later, “Parallels” still has no equal in this specific category of franchise installments.

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