It's one of those movies that you'll want to watch again as soon as you finish watching it, not for intensity and depth, but for a deeper look at the layers and nuances you've likely missed.
That tag line is 'secrets lie between the lines'; the movie gives us a sideways view into those between the lines spaces....of a close and loving relationship, paradoxically one of great joy and deep pain..... the conflicts that ensue from that space...between the two, and more so within.
The 'within' as can be seen from title, is the wife's, who after four decades of marriage, seems to now be ready to look at the true nature of their relationship, and confront and deal with some decisions she's made, while continuing to being the loving wife she's always been........ almost wondering why.
Glenn Close is so brilliant in performance that you can almost see the complex series of thoughts running through her head. Amazing performance.
Definitely watch !!