Nine years ago a little miracle happened. An American boy and a French girl met up on a train in Vienna and spent a wonderful day together talking about everything under the sun, slowly falling in love and eventually making love together in a park just before sunrise. They parted with youthful zeal, fully expecting serendipity to work its magic and allow them to meet once again, six months later, at a pre-determined time and place.
The miracle was a movie: Richard Linklater's Before Sunrise, starring Ethan Hawke and Julie Delpy. We were left to speculate what would happen in six months. W…