I know the ending of my HP opus now. In fact, I know two endings: one happy, one not, and it will affect the tone of the rest whether I opt for comedy or tragedy. (Comedy in the Dantean sense: something that goes from bad to good, not in the sitcom sense.)
I'm quite excited about my ending; the opus didn't have an ending before, it just sort of fizzled out -- and I believe in strong endings, big climaxes, and love it when I happen upon the perfect last line. Which I haven't yet but I've got the ending (two endings).
And no, I will not post both endings.
I realised that I didn't like the two-endings post-modern approach to posting when
As to my own two endings, thinking about them has sharpened my perception about the fic and about the characters. I can't have two alternative endings. Two alternative endings would mean two alternative fics as the ending should (I think) arise logically and seemingly inevitably out of the characters and what they have done up to the ending. Otherwise, the ending is not aesthetically satisfying.
So my choices are two:
1) Write the happy ending. This makes most people happy and will gain me more readers. This also makes me happy. I started sifting through all my fics in my head and they all have happy endings. (Except for one of my unfinished WIPs.) Happy endings are satisfying and moving and make me want to re-read, and they lend a happy glow to life.
On the other hand, if you have a triangle story, it will have to end unhappily for somebody. So it becomes a decision about whom to sacrifice. T'HP opus is a triangle story. A Perfect Day was a triangle story, and a lot of readers were dismayed that one of the pairing-characters lost out to the other pairing-character. So even though for me and for the guys that got each other that was the right and the happy ending, it wasn't so happy for they guy who didn't get the guy.
2) So I could write the sad ending. Sad endings resonate and have a certain gritty reality factor. They seem more 'real' than the happy endings. They make readers shout and plead and react. They make readers continue the stories in their heads in order to force a happy ending later down the line. I have loved some sad-ending stories but I tend not to re-read them because they are too upsetting.
Otoh, the two characters whom I want to bring together for my happy ending are not beloved of most readers, so readers may actually think that the sad ending (where this particular pairing is torn asunder) is the happier one!
See? It's not simple! But it's interesting. And it makes me ponder the characters. Because in the end only they can tell me how they're going to act and what the ending is going to be. And the way they're going to act arises from the way they are, and they are that way from the first line of the fic. And I can't have two alternative beginnings as well!
Well, I could but I'm not writing When on a winter's night a traveller -- which is, btw, one of my top ten novels and omg, it was the inspiration for one of my other top ten novels, as I found out only today.