Just a quick post today about theme and how it’s different to plot. Writers way smarter and way more talented than me have ideas about this, but here’s my perspective.
First of all, yes, these things are quite different. Most people agree with that. I find that often a poor short story by a new writer has no theme. It’s just a story. In a good one there’s maybe a few nice emotional beats but overall, it’s quite flat.
In some ways, the theme is what you’re left with as a reader. The story comes and goes, but there’s a wider idea – emotional or otherwise – that you’re left with as a result. To put it in embarrassingly simple terms, the plot is what you’d describe when someone asks, “What’s your story about?” … The theme is what you describe when that same person’s follow-up question is, “Yeah, but what is it really about?” Does that make sense? Or any I being too simplistic?
A story with a really good theme will often influence the end of the plot, but also it can make the end of the story less important, and not in a bad way. Often the real climax of a story is just a bit before the end. Maybe – though obviously not always – the end of the penultimate chapter is the end of the plot. But the final chapter – possibly an epilogue – is there and feels really necessary because of the theme.
If there’s no consideration to the theme, then you might be only interested in nailing that ending and getting out. Nothing wrong with doing that. But if the theme is strong, then that can dictate when the ending occurs. It can be before or after the end of the actual plot.