The Big Dark Moment

In a romance, the Big Dark Moment is the crucial juncture when all seems lost between the hero and heroine.  He stomps away and she strides in the opposite direction, and it seems as though they will never be together again.  How can they overcome their insurmountable obstacles?  Will love triumph in the end?

Of course it will.  The prerequisite for a romance is the HEA  (Happy Ever After) ending. But for this HEA to have emotional impact, our characters first must experience the painful Big D...