Twisted Ghosts

I'm busy writing my ghost story of a novel "Grey House" and realize that I only have a beginning and a middle.  Granted these are two major stepping stones in order to find my way to the end but do you need an end to have the first two?  Confusing, I know.  Let me explain.  It's common ,and by common I mean a couple people in a room somewhere once posted it on the internet and now it's gone viral,  knowledge that for a mystery novel that you should have an end game in sight.  That it's a good idea to know the ending so you can leave clues along the way.  A ghost story is like a mystery novel, in that it requires clues or hints along the way.

I wonder if movies like "The Sixth Sense" or "The Others" have changed the game of ghost stories.  Is that big dramatic twist at the end necessary for the ride to be worth it?

In every story there's 'ah ha' moments, that's a given.  I still have a story to tell, I just don't have the great revelation at the end to tie it all together in a nice movie sort of way.  Granted there's still a lot of writing between now and when I'm at the end so anything's possible.  I'm only 7,000 words into what I hope turns out to be 60,000, or so.

What say you, my faithful readers...ur...reader, is a twist the new normal for ghost stories?

PS - thought of this, thought it was funny (it's late, my time, 12:30, ya'll, give me a break)  "You got your twist in my ghost story."  "No way, you got your ghost story in my twist!"