Please bear with me while I geek out about Edith Keeler in "The City on the Edge of Forever" for a moment.
It almost feels unnecessary to rave about "The City on the Edge of Forever" (S1E28) again, since it has been praised as one of the all-time best episodes of Star Trek for like 50+ years now, but I just rewatched it and want to specifically talk about how much I love the character Edith Keeler.
(If you haven't seen the episode, or it has been too long, some quick context: This is the one where they go back in time to 1930 and meet Edith Keeler, who is running a shelter.)
Within the first few few minutes that Edith is on screen, you find out that she's not only incredibly kind but also insightful and filled with hope about the future. She's a dreamer who tries to excitedly tell everyone about the things she believes humanity will accomplish in the years to come, including space exploration.
It's hard to watch this episode and not feel bad for Edith - dreaming of all these things while being stuck in the 1930s - knowing that she won't get to see the world that Kirk and Spock have traveled from. Then, for the first time, I realized that this makes her the perfect stand-in for the audience. My thought-process went from feeling bad for her in the 1930s -> to feeling bad for the people watching Star Trek in the 1960s -> to realizing that I'm watching this episode nearly 60 years later and am still living far too early to experience the times she's dreaming about. We are Edith Keeler.
This gave me a new appreciation for what they did with this episode, the series as a whole, and specifically Edith Keeler's character. Her inspiring and hopeful attitude truly represents the heart of what makes Star Trek so captivating.
I suppose not... but part of me still wishes they had been able to save her. Although I recognize that it wouldn't have been as good of a story if they had.