Having finally seen both parts, I can confirm these films need to be seen in the order traditionally screened, with
Him first followed by
Her.
I thought the overall experience was an interesting experiment, one that didn't fall too heavily on what could quickly become a simplistic he said / she said gimmick in execution.
Him charts a blindside breakup from James McAvoy's perspective as the dumped, struggling to get questions and acclimate himself to the reality that it's over. Then
Her, perversely, acts as a form of reluctant wish fulfillment on the part of anyone who's ever been dumped, in that it gives us the answers to our ex's irrational behaviors and explains why they did what they did. Only there's no satisfaction in the totality of information offered because on a basic level, the impetuses behind the act of cutting things off are as much a mystery to Jessica Chastain's character as they are to McAvoy. We want answers and closure in a breakup, but is it better or worse to realize so does the person who initiated it? The possible answers lobbed about here, including most prominently a dead child, would be the easy and obvious answers in a less realistic film. These movies however take a more level, if somewhat frustrating stance: sometimes a relationship dies and it is just over, and yet we find ourselves drawn to this other person still, whether or not it's fair to ourselves or them. It's part of what makes the end of the first film so wonderful
as McAvoy being stalked by Chastain through his early evening walk is a smart metaphor for the inescapable nature of some relationships in our psyche ("the one that got away"), even when things seem to be better and we've ostensibly "moved on," the memory of them follows us.
There are a handful of scenes shared between the two films, with most playing out in slightly altered fashion from one another, indicating a change in either perspective or memory, but this isn't the focal point of the film's methodology. Rather, the film presents two sides of a breakup, neither particularly able to stand on its own (Unexpectedly of the two,
Him functions okay as a stand-alone, but
Her would make no real sense apart or before
Him. This could be read as purposeful in that ultimately the actions of McAvoy make more concrete and conventional narrative sense, something already reflected in how he handled earlier crises in the film) but together forming an intriguing attempt at replicating the impossible
totality of understanding the death of a relationship. While the overall experience asks for nearly three and a half hours of our time only to arrive at mostly unanswered (and unanswerable) questions, the rewards are there for those who've been on either side of this sort of thing.