Initial Idea 2

I have another idea which i think could also use my garden shed which i think is really good as it's really quite creepy (i don't like going into it in daylight).

This idea is a little more vague than my first one, but basically the event happening in it would be someone discovering something very disturbing happening in the shed. So possibly it is a girl and her boyfriend is secretly a serial killer, and he has told her not to go into it but (obviously)she does it anyway and then at the end of the opening sequence he finds her snooping and we hear screaming (and then it jumps to earlier or later in the film).