The plot looked fairly straightforward, but the magic of this gem is that the story strand convolutes until it tightens into a strangling gordic knot - which is pretty much exactly what happens towards the end. The flashback structure are very noir-ish, so was the plot - everything straight down, right from the beginning. I really rooted for the guy to get out of this situation, but every time he takes a decision it actually gets worse - so in the end I was just hoping he might die and get relieved.
Most striking was the jaw-dropping performance of Ann Savage. She pops out about a mile and her character is rendered so immensely unlikeable that I wondered that she has not been called the godmother of a new type of acting school (maybe she was?)
This is definitively a film worth studying again. Its shortness does nothing to diminish the impact and it is rich on details.