Hey all that research on "theme" is helping. Bizarro! (Bonus reference for Sealab 2021 fans)
A technique that worked well this time is that I wrote 2/3 exploratory-style on the computer and then grabbed a paper notebook and listed all the things I knew to be true. Then I found the ending by combining all that stuff together, like a twisted game of connect the dots.
Once I figured out what I wanted to say with this story, it was easier to rip out the extra bits and rewrite sentences, knowing exactly what I needed to include and what I didn't.
Approaching short story writing as if it were a mystery that needed to be solved seems to have worked well for me. Having said that, the true test will be if the story works for anybody else.
It amazes me how humbling this is, learning to write fiction. I've only been seriously at it for eight months, and only about four of those months were spent actively trying to become involved in the community and taking classes.
I feel like I'm just beginning to see what's possible.