Initial teaser trailer ideas/ plot synopsis

I have decided to construct a trailer of the thiller genre, subgenre horror.
I have taken great inspiration from the trailers i have analysed, specifically the last exorcism and shutter island.
The narrative is going to revolve around a group of friends that have recently moved into a new flat. Strange events begin to occur as the friends become more and more convinced that there is something wrong.
The idea of the trailer is that small things happen such as doors banging, pictures moving, objects falling (similar to that of paranormal activity) but they all add up to a climax at the end of the film that one of the friends has actually been possessed by something (perhaps the girl) within the flat and is subconciously making these events occur.
The trailer is going to begin with the friends light heartedly talking and moving into the new place with fades onto newspaper clippings etc of information about a young girl that died in the flat before they moved in, words such as mystery and shocking fades into one another. There will then be a close up of one of the friends locking the door to the new flat. then the tone of the trailer changes as the events begin to occur (doors banging etc) Throughout the trailer the pace is going to quicken as more things start to happen and at a point within the trailer the pace is going to completely slow down as a bedroom door creaks open and there is a shadow of one of the flatmates standing in the doorway.
Within the trailer also there will be close ups of scared faces, hands picking at finger nails all to show the nervous/tense atmousphere. At some point there will be a point of view shot of somebody running and breathing heavily outside to indicate that somebody is trying to get away from something. There will also be a point in the trailer where there is a long shot of a girl standing in the flat gardens looking up at the flat accompnied with a burst of tense music, this will indicate that this is perhaps the girl who died in the flat.
The mise en scene will be quite naturalistic to indicate that this group of friends lead normal lives but as the trailer progresses the lighting will change becoming darker and indicating more mystery until the end shot of the dark figure standing in the doorway.
Throughout the trailer also sentences of texts will appear after certain camera shots in the trailer, my initial idea for this text is 'What happens when...' 'The people you trust...' 'Become the people you fear...'