WMG / Star Trek: The Next Generation S3E15 "Yesterday's Enterprise"

• Is the bad timeline an alternative universe to the regular one and by sending the Enterprise-C back in time we 'restore' the timeline to what it should be... or is "our" universe, in fact, the alternative universe to the true course of events, which included the disappearance of the Enterprise-C and a long bloody war with the Klingons? In other words, have we actually been watching an alternative timeline all along? The episode is surprisingly ambiguous, leaving the viewer to make their own mind up. (Perhaps the best-case scenario is that both timelines are equally valid, they merely branch off from one another 'for want of a nail'.)

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