By Terry Terrones Published Oct 24, 2026, 9:20 PM EDT Terry Terrones is an entertainment writer for Polygon. His work has appeared in The Hollywood Reporter, Parade Magazine, Paste Magazine, Entertainment Weekly, The A.V. Club, The Wrap, TV Insider, and other national outlets. He is a member of the Television Critics Association, the Critics Choice Association, and the National Association of Hispanic Journalists. Opinion This Captain Kirk speech says more about what Star Trek stands for than any other line in the original series.
Image: Paramount Add Polygon.com on Google Add as Preferred Source Follow on Google Discover Sign in to your Polygon.com account Like Like follow Follow followed Followed Thread 7 Log in Here is a fact-based summary of the story contents: Try something different: Show me the facts Explain it like I’m 5 Give me a lighthearted recap Certain lines of dialogue become so famous they almost stop belonging to the movies and TV shows that produced them. “May the Force be with you.” “I’ll be back.” “You're gonna need a bigger boat.” You don't need to know the context. The words have long since transcended their original context.
Star Trek: The Original Series has plenty of those. Spock’s wish that everyone to “live long and prosper” is arguably the franchise's signature phrase. He also turned the simple word “fascinating” into a catchphrase simply by raising one eyebrow before saying it. Dr. McCoy (DeForest Kelley) spent three seasons reminding everyone, “I'm a doctor, not a…” and, at least in our collective memory declaring, “He's dead, Jim” while standing over the latest redshirt who wandered a little too far from the landing party.
But if I could only pick one line to represent everything Star Trek stands for, it would be four simple words spoken by Captain James T. Kirk (William Shatner) halfway through “Return to Tomorrow," the 20th episode of season 2:
On the surface, it doesn't seem like an obvious choice. It's not printed on T-shirts nearly as often as “live long and prosper.” It isn't endlessly quoted by people who have never watched an episode of Star Trek . And unlike “beam me up, Scotty,” it never became part of the broader pop culture vocabulary. But that's exactly why it's the best quote. It doesn't just capture Kirk. It captures the entire philosophy of Star Trek.
First broadcast on Feb. 9, 1968, the episode “Return to Tomorrow” finds the Enterprise answering a mysterious distress call from a dead planet. There, Kirk and his crew discover Sargon, one of three survivors of an ancient civilization that has existed as beings of pure energy for half a million years. Sargon asks Kirk, Spock (Leonard Nimoy), and Dr. Ann Mulhall (Diana Muldaur) to temporarily surrender their bodies so he, his wife Thalassa, and the ambitious Henoch can build android bodies and begin life again. Dr. McCoy believes the aliens are manipulating them. Kirk believes the chance to learn from a civilization hundreds of thousands of years more advanced than humanity is worth the danger.
Image: CBS The episode also marks the first of three Star Trek appearances by Diana Muldaur. She plays Dr. Ann Mulhall here before returning as Miranda Jones in the third season episode “Is There in Truth No Beauty?” Years later, she'd become a series regular on Star Trek: The Next Generation as Dr. Katherine Pulaski. “Return to Tomorrow” is also a fun piece of Trek trivia because it's one of the times Spock describes Sargon as “pure energy,” a phr…