If you had a perfect plot to write what would be about

I think that I would love to write an horror movie in the style of home invasion. The plots would be a women who live alone and one day she see a guy that just fall in love with her, she work in a coffee shop and the guy will start to stalk her at her house and at her work. One day he try to brake in her house and he loose his missions so know he sleep at the back of the coffee shop without her knowing that. She already Know that she's been followed and she is going to disciver by who and she will try to escape.