The Best Star Trek Episode For Fans Of Great Sci-Fi

By Chris Snellgrove | Published

Star Trek Enterprise model

One of the reasons that Star Trek has become so popular is that it has many episodes and movies that even the most casual audiences can appreciate. This has led to the ironic development that even though this is the most famous sci-fi franchise, it can be difficult to find episodes for hardcore science-fiction fans to enjoy. I looked back through the history of Star Trek (over 900 episodes and counting!) and decided that the best adventure for sci-fi fans in particular is The Original Series episode “City On the Edge of Forever.”

The Episode

city on the edge of forever

Before I can dive into why it will appeal to sci-fi fans, I need to quickly review what “City On the Edge of Forever” is all about. The Enterprise discovers a planet that is home to the Guardian of Forever, a kind of living doorway through which someone can visit any time or place.

When a drugged Dr. McCoy goes through the portal and changes history, Kirk and Spock follow him back into New York City in 1930 on a quest to save the future as they know it.

An Alternate History

city on the edge of forever

Let’s cut right to it: what makes “City On the Edge of Forever” the best Star Trek episode for fans who appreciate great sci-fi? For one thing, this is one of the franchise’s first (and still its best) portrayals of an alternate history, making it a great episode for those who enjoy such novels as the Philip K. Dick’s The Man In the High Castle.

That novel imagines a world where the Axis won World War II, and that’s the exact future that McCoy accidentally causes and that Kirk will do anything to prevent.

Sci-Fi Shouldn’t Forget Humanity

city on the edge of forever

I’m going to delve into some spoilers now, but another reason “City On the Edge of Forever” is great for sci-fi fans is that it never loses sight of its humanity. Some sci-fi can be colder than I’d like (looking at you here, Asimov), and I think the best sci-fi novels are ones with very human and relatable characters (The Handmaid’s Tale and The Hitchhiker’s Guide to the Galaxy are tonally very different but both exemplify this).

In this Star Trek episode, everything comes down to an awful decision Kirk must make, one that both humanizes and haunts this iconic character.

Letting Edith Keeler Die

Kirk and Spock eventually discover a terrible truth: all Dr. McCoy did to change the future was to save the life of Edith Keeler. She’s a soup kitchen volunteer who goes on to create a successful pacifist movement that delays America from entering World War II, allowing the Nazis to develop an atomic bomb first and effectively take over the world.

In order to keep that from happening and save the future, Kirk must hold McCoy back, keeping the doctor from saving Keeler.

A Near Perfect Trek Episode

Your mileage may vary, of course, but as a sci-fi nerd myself, I enjoy stories where characters must balance their personal morality with high-stakes decisions. In choosing to let Keeler (who, incidentally, he had fallen in love with) die in order to save the future, Kirk’s decision reminds me of other sci-fi icons and their own hard decisions.

In this moment, he is Winston Smith in 1984 betraying Julia–at the same time, he is John in Brave New World, choosing a life of unhappiness rather than everyone else’s vapid fantasies.

Obviously, taste is subjective, and there are probably some sci-fi fans who wouldn’t grok “City On the Edge of Forever” because it’s less about technology and more about history and humanity.

However, those are the episode’s greatest strengths, and focusing on these qualities has created some of the best sci-fi stories ever made.

In fact, I’ll go a step further: by watching this legendary Star Trek episode, you won’t just get a great story–you’ll get a narrative that has charmed and influenced some of your favorite sci-fi writers, inspiring them to create their own timeless tales.