Watching Kenneth Lonergan’s new Manchester by the Sea, a tremendously moving drama about the relentlessness of grief, rich with nuance, depth and unexpected humour, you can’t help but be in constant awe of the director’s craft. Lonergan might be working with a fairly conventional subject—indeed, on paper, the story doesn’t particularly pop—but, by maintaining his focus on the people, and revealing them in all their conflicted, contradictory, complex glory, he’s turned something simple into something so layered and immersive that it’s actually a bit disorienting to step back into your own reality when credits start to roll. He might have helmed just two previous features, much more prolific in his theatre outings instead, but this flair for substantive character studies rather than big cinematic “moments” as such has always been evident in his exertions. And in this new film, more than ever before, Lonergan has the support of a dream team of performers who perfectly fit that sort of minimalist, stripped-down vibe he’s going for.

Lee Chandler (Casey Affleck) doesn’t make a great first impression. A custodian working in Boston, he seems like, well, a bit of a misanthrope: he barely smiles at the people in the apartments he’s tasked with servicing, doesn’t respond when a pretty girl tries to flirt with him at a bar, and picks entirely unnecessary fistfights with strangers, before going back to his sparse basement lodging and falling asleep on the sofa with the TV on. But when, one day, he receives a call informing him that older brother Joe (Kyle Chandler), who has been battling congestive heart failure for a while now, has passed away, he must force himself out of his dreary little bubble and go back home.

Home being the titular Manchester-by-the-Sea, just an hour or so away by car, but a whole other planet as far as Lee is concerned.

The trip is full of surprises. Not only is he solely responsible for handling all the funeral arrangements, but—and this is the real kicker—Lee also discovers that Joe has made him legal guardian of his 16-year-old son, Patrick (Lucas Hedges). Lee, already having a rough time confronting a past he had thought he had well and truly buried in exiling himself from his hometown, is understandably overwhelmed by the responsibility—“I was just a back-up,” he tells Joe’s lawyer mournfully—but he also loves his brother far too much to just walk away. And so, uncle and nephew must now co-habitate—temporarily, Lee hopes, determined to eventually convince Patrick to move with him to Boston, though the latter is intent on staying put, because, as he so eloquently explains: “All my friends are here. I’ve got two girlfriends. I’m in a band. You’re a janitor.”

Although cinematographer Jody Lee Lipes succeeds in giving us a sense of what it must be like to live in  this chilly coastal town, all grey skies over metallic seas, and ice-slicked roads lined with frosty trees and equally frosty-looking houses—the bleakness of which is made particularly evident in the frequent wide shots—the setting also kind of doesn’t matter. Because the story is so skillfully intimate that it’s not especially tethered to a time and place: sort of like tragedy and loss itself, it feels like it could happen anywhere, to anyone.

And it’s that achievement of universality within specificity that lies at the core of Manchester’s effectiveness—and, of course, Lonergan’s uncanny eye and ear for the cadences of human behaviour, the stuff that constitutes the daily business of walking and talking in the real world. There’s no striving for unnatural eloquence or profundity in dialogues here—they’re messy, jerky, people often talking over one another, the way it is when you’re dealing with actual flesh and blood. This is never more apparent than in the way the film captures Lee’s alienation, the way any social interaction seems to almost take a physical toll on him: there are multiple sequences of him standing around trying unsuccessfully to make small talk with people, moments that Lonergan deliberately prolongs to their absolute limits in a bid to really acquaint us with the character’s constant malaise, the bumpy awkwardness between him and everyone else.

Overall, too, rather than the sort of dramatic epiphanies and heart warming speeches that would have otherwise littered a film like this, then, the writer-director chooses to focus on the smaller, more mundane, but very real, moments in between the bigger life-events. For instance, following Joe’s passing, instead of dwelling too keenly on the emotional implications of the loss, or overtly romanticising the dead man, the script is more interested in the practical matters that follow a death, the checklist of depressing phone calls to make and forms to fill and other smaller headaches in the process that other films might have been content to skip over. Even the flashbacks that have been woven intermittently into the story have a matter-of-fact quality about them, cutting in and cutting out with minimal fanfare. Of course, all this isn’t to say that the film is entirely bereft of big, high-emotion notes: it’s just a slow, slow burn leading up to them, so that when they are hit, they feel authentic and their impact fully earned.

The cast serve to notch up that authenticity; all are terrific, but none more so than Affleck. In gradually unpacking Lee’s mind and motivations, the actor is able to make him feel whole, a living, breathing, hurting person, real enough to touch. It’s not that Affleck has had a bad run or anything—he’s bagged some pretty high praise for his work in The Assassination of Jesse James by the Coward Robert Ford and Gone Baby Gone, among other projects—but never has he worn a role, so completely inhabited it, like he does in Manchester. He has a wonderful foil in the far more lively Hedges, whom you might remember from Moonrise Kingdom, and who boasts the wry, semi-smug charisma of a young Matt Damon. We also have Michelle Williams in a small, but memorable, role here, along with Chandler, whom we see in flashbacks. Gretchen Mol and Matthew Broderick’s stints, however, feel a little overdone, but these are mercifully shortlived.

I’ll admit Manchester by the Sea doesn’t really sound like a great deal of fun, and one could definitely argue that nothing actually “happens” in the customary dramatic sense for most of the film. But if you’re able to get with that sort of discordant, almost-clumsy tempo that it employs—one that mimics the unevenness of life itself, where things don’t always unfold in a straight, clear, narratively-sensible order, and where humour can be located even in the blackest of tragedies—then you’ll be rewarded for sure.