Editing, editing, editing

After finally finishing the second draft of my book, I am now editing its very first pages.  Interestingly, it is not merely a matter of tightening and polishing the language.  The whole setup  has to be altered considerably.  I'm not surprised by this because I pretty much expected that I had to finish writing the entire novel, and especially its ending, before I truly knew what needed to be said in the first chapter.  In fact, it seems like a good idea to write a complex story in a sort of zig-zag pattern—somehow the mark of Zorro comes to mind—with the first draft going from beginning to end, the second draft from end to beginning and the final draft again from beginning to end.
I started out with a fairly good idea of what the story was going to be and how it would end, and I wrote the first chapter in accordance with that vision.  But then my characters took over and led me down paths that I didn't anticipate, caused all sorts of trouble I never saw coming, and twisted my story into something I hardly recognized.  Before I knew it, my first chapter did no longer do a decent job at setting the reader up for what was to follow.
So now I am back at the beginning to make the necessary changes—thus knocking over the first domino block in a long row of heaven knows how many more blocks, because, alas, one change always leads to another.  And as I thus work my way through my manuscript, I only pray that this ever changing story will not need yet another new beginning once I reach the end, setting off another—ahh, perish the thought!