The Terminator TV show The Sarah Connor Chronicles has a pretty big time travel plot hole, and the reason behind it is stupid. Like any time travel-based franchise, theTerminator series has had some trouble keeping its rules straight. Sometimes everything is presented as a stable time loop, where everything in the past and future has already happened, thus making Kyle Reese always somehow destined to be John Connor's father. Other times, Terminator leans on the idea of the future not being set, hence Sarah's drive to prevent Skynet from existing at all.
One of the clearest, and thankfully least complicated of the Terminator franchise's time travel tenets though is the idea that only organic matter can travel through time. Or at least through the portals that exist in the future where John Connor is the leader of the human resistance. That's why, dating back to the first Terminator movie, anyone who goes through has to go through naked. As for the T-800, its ability to go through is explained away by its endoskeleton being surrounded by living flesh.
Related: Terminator: Every Character Who Says «Come With Me If You Want To Live»
For the most part, FOX's short-lived TV show The Sarah Connor Chronicles is a quite worthy addition to the franchise. It's been ignored by subsequent movies, but the story it told over its 31 episodes was well-paced and plotted, and felt like a Terminator entry. Unfortunately, there's a huge plot hole found in the first couple of episodes that's never even mentioned, much less resolved. Near the end of the pilot, Sarah, John, and new ally Cameron (Summer Glau) blow Cromartie the Terminator to pieces right before traveling through time. Yet, Cromartie's head goes flying through the portal after
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