Star Trek: 15 Greatest Ever Time Travel Episodes
2. The City On The Edge Of Forever - The Original Series
In a very close run thing, this Original Series classic would probably win a time travel run-down with a lot of Trek fans. It's important to acknowledge that fact, and that this is easily one of the greatest Star Trek episodes ever made.
The City On The Edge Of Forever is not only a great Star Trek episode, it's also a great time travel sci-fi story, featuring romance, drama and intrigue. It has humanist interests, moral dilemmas and the ultimate causality problem - that someone fated to die would survive and unwittingly allow the Nazis to win World War II. Naturally, Kirk falls in love with said person, because of course he did, but that heart-wrenchingly means he has to allow her death in the end.
The message, very much like the stark, devastating ending to On Her Majesty's Secret Service, is that being a heroic decision maker comes with massive costs. And also that time travel and causality are a cold, relentless mistress.
The episode rightly won multiple awards and proved that old narrative devices can still work wonderfully when they're written well.