Weekend Reads, Or When A Book Ends With a Bang, a BAD Bang

So I just finished reading a book that will be reviewed a few weeks.  I loved it, really loved it.  I've tried reading other books by this same author but couldn't get into them.  And then this one came along and, well, captured my heart.  I grew to know and love the characters, and I cared about what they were trying to do.  And then came the ending.

"Something big" is going down and most of the characters are laying in wait for it.  They have no plan whatsoever if this "something big" doesn't work out.  And then BAM.  Something totally unexpected happens to the people doing this "something big" and then the book just ends.  It ends!  Just like that.  No speculation as to what the other characters might do.  No afterword.  No nothing.  It's driving me crazy.  I had to sit down and read Cosmo for an hour to try to forget about this ending. 

I've been trying to console myself by making up what I think would have happened to the remaining characters based on their personalities and the predicament they were in, which helps a bit.  But not much.

So my question to you is, what do you do when a book ends so abruptly that you can't stand it and have no idea what happens to the main characters??