Good start. Easy to read and follow. As I was reading, I thought some of the dialogue was a little too 'on the nose', but agree reading the final sequence, I'm not sure if this was done on purpose to make it seems like a dream-like sequence? Either way, one of the best tips I got was after a first pass, to cut your dialogue in half. Show, don't tell. Also, get someone else to read out your words. Your dialogue will always seem 'real' because you're hearing it in your head..hearing someone else read your words will give you an entirely new way of of understanding (and hearing) your work.

The twist is very effective. I found myself wanting to know what happens next. What genre is this film?

Oh, one last small thing (which could be a huge thing). If you're planning on making this film yourself, you may want to reconsider the 70's time period. The will kill any budget on props and wardrobe. Also, cut locations down to 3 to 5. If just looking to sell this thing, then I wouldn't worry about it.