Fittingly, the finest moment in this epic film, all two and a half hours of it, is the assassination scene, James, Ford and his brother Charley moving around and taking their appointed places in James' sun-filled sitting room as if propelled by slowly unwinding clockwork, Cave and Ellis' melancholy score coiling and redoubling upon itself all the while, until at last, the gunshot, the long deferred end towards which everything else to that point has been a single extended dying fall - at its best, Assassination is slow burning and magnificent.
A western but then not, with shades of a character study but ultimately inclined to leave its central figures undeciphered, oriented from its very title towards a single, inevitable action but content to take a series of divergent, meandering paths along the way, shot through with some of the most astonishing landscape cinematography I've seen in a long time, it's soaringly ambitious - and almost, almost pulls it off. That it doesn't quite get there can only be attributed to something ineffable - a subtle failure to completely coalesce, somehow - but even so it's a real achievement.
Brad Pitt and Casey Affleck dominate affairs, whether when onscreen or by their absence, their uneasy relationship the tense central spring from which the narrative derives much of both its immediate and ongoing drive, but the film doesn't play as a two-hander; rather, a whole cast of others move prominently through events, appearing and recurring at intervals. Indeed, those supporting characters are a huge strength of the film - they're uniformly economically but effectively written and drawn, portrayed and inhabited by an understatedly brilliant cast (though, not really a propos, I must confess to being disappointed that Mary-Louise Parker and Zooey Deschanel, two of the cutest female actors going around today, didn't get more screen time).