There is a moment of silent incompatibility in Joe Swanberg's Drinking Buddies that illuminates the entirety of a relationship in a single request. As the lovely, earthy Kate (Olivia Wilde) reclines suggestively on a couch in his tasteful apartment, Chris (Ron Livingston), her gently fussy boyfriend, politely reminds her to put a coaster underneath her beer. It doesn't sound quite like dramatic cinema, yet through Swanberg's inquisitive, probing gaze, the truth shouts itself: Kate and Chris are on borrowed time. What's more, while their incompatibility is apparent to the audience, the lovers themselves are clueless to it.

With dexterity and care, Swanberg illuminates our muddled perceptions of our own relationships. He fixates on the minutiae of hanging out, the stuff of little loves and lies, the feints and thrusts we make in sorting matters of head and heart. His conflicted central characters are Kate and Luke (Jake Johnson), co-workers at a Chicago brewery. We're quickly initiated to the casual rhythms of their lives — shooting the shit with co-workers, pool at the local bar.

Luke and Kate seem perfect for one another, but since they're both in serious relationships, neither will make the leap and acknowledge the flighty sexual tension between them.

Crucially, Kate's and Luke's significant others are a notch or two down on the totem pole of hipness. If Luke's girlfriend, Jill (Anna Kendrick), and Chris are happy to grab small-batch ales at the pub before they get to bed at a reasonable hour, Luke and Kate are more likely to close the place down.

The foursome heads off for a weekend at Chris' beach house, but if you think you know where this is going, you're probably mistaken.

Only moderately concerned with plot machinations, Swanberg is far more enamored with the feeling of an honest moment. He relishes people being people. Particularly effective is a crosscut sequence in which Luke and Kate, drunk in the cabin, build the most disgustingly huge sandwiches they can concoct while Chris and Jill enjoy a refined picnic in the woods, aided by Jill's backpack-cum–utensils set. Such moments bristle with the rhythm and verve of subtle flirtation, the characters caught in a pull toward one another that they know they should fight but cannot. Denying real sexual attraction is never anyone's idea of fun, and later that night, in Luke's pained expression as he watches Kate skinny-dipping, we can read a kind of regret over the unlived life.

Much of this picture's charm comes from the full tangibility of these characters' feelings — the heights of their joy and the depths of their despondency. Swanberg never works with scripts — he writes an outline for the film and lets his performers fill in the dialogue, imbuing the scenes with a potent realism that at times feels practically documentary-like.

In some of Swanberg's earlier work, the freewheeling nature of his dramaturgy was marred by the equally freewheeling nature of the productions — shoestring budgets, shaky lo-fi video camerawork that often distracted audiences from fully engaging with the actors. Happily, a larger budget has enabled Swanberg to do his thing with greater efficacy than ever before — this time, his camerawork is always well lit and, rather than obstructing his actors, it creates a simplicity that lets them command everything else.

There's some irony in the fact that Swanberg, the archetypal champion of microbudget cinema, has made his greatest film in his first at-bat in the financial big leagues. Yet it's also telling that, for all its movie stars and production value, Drinking Buddies fits comfortably within Swanberg's growing niche oeuvre. As we live inside the roller coaster of Luke and Kate's hot-and-cold rhythms, the push-pull of will they/won't they — they're having a sleepover! But they don't kiss! Now they're making romantic dinner plans! But Kate's calling it off! — their torturous, conflicting feelings begin to assume a monumental, generational significance that recalls many of Swanberg's previous works.

He has built a career analyzing (white, metropolitan) 20-somethings as they struggle to determine whom to love and who loves them back, conflicts they feel carry life-or-death stakes. Yet in Drinking Buddies Swanberg's careful eye perceives the nuances of those conflicts with greater perspicacity than ever before; never have his tiny moments of truth felt so honest or clear. Who would have thought using a coaster might make all the difference?

DRINKING BUDDIES | Written and directed by Joe Swanberg | Magnolia Pictures | Nuart, and on-demand

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