In Manchester by the Sea, the powerful third film from master dramatist Kenneth Lonergan, Boston area property manager Lee Chandler (Casey Affleck) is forced to confront the triggering memories of his past mistakes and traumas. He returns to his coastal Massachusetts hometown following the death of his older brother (Kyle Chandler, glimpsed in flashbacks throughout Lonergan’s subtle, time shifting narrative) and the unexpected legal guardianship of his teenage nephew, Patrick (Lucas Hedges). Lee, a solitary man by design after his marriage to his ex-wife Randi (Michelle Williams) came to a disastrous, heartwrenching end, wants nothing to do with Patrick. Similarly, Patrick doesn’t want Lee to be his guardian because that would entail him leaving all his friends (and girlfriends) behind.

I don’t want to give away too much about Manchester by the Sea, but it’s a hard film to talk about in all its humanist reverence without giving away the major reveal around the film’s halfway point about what drove Lee and Randi apart. While the death of the level headed, understanding, patient older brother is certainly a tragedy, it’s made known up front as a sort of sadly inevitable conclusion. The true pain of the film comes from witnessing how broken Lee became before that event. It all unfolds in one of the most operatic, haunting sequences in a film this year, one that should get the tongues of awards season pundits wagging based on the power of that single scene alone.

So while I’ll leave a close reading of Lonergan’s latest for another day, I will say that there’s plenty more to talk about and celebrate without spoiling the impact of the film. Lonergan (You Can Count on Me, Margaret) and his cast have created one of the most dramatically satisfying depictions of loss, survivor guilt, and the grieving process ever committed to cinema. There’s not a false note to be found, with each scene feeling like a subtle revisiting of a loved one’s grave site. Like most great drama, the performance and artifice drips away, and all that’s left in Manchester by the Sea is a memory of times gone by and cautious hope for the future.

While Williams reminds viewers why she’s one of the best actresses of her generation in her relatively small amount of screen time, it’s the already reliable and perennially underrated Affleck who delivers some startling, career best work. He’s great in sequences when he’s reliving the marital bliss of his past, and he’s better in his scenes opposite a star making turn from rising star Hedges, with their witty, sometimes bleakly comic repartee providing the film with much of its heart and backbone. He’s best, however, in his portrayal of Lee as an irrevocably broken man.

Present day Lee refuses to make eye contact with people, and carries with him a metaphorical cloud of shame that Manchester’s residents have labelled him with. He thinks everyone talks about him behind his back and can be prone to fits of rage either founded or completely baseless. When confronted on his B.S. or confronted by the fact that he can’t move on, he’ll often offer up a half-hearted “Oh…” before trailing off and failing to finish his sentence. His means of keeping things together have created a completely internalized human being, and Affleck mounts a masterclass in how to create a well rounded character out of a bundle of subtle tics, neuroses, and traits.

It helps that Lonergan has crafted some of the best scripts of the decade and that his material gives actors quite often so much to work with that it’s impossible to know what to do with it all. His work behind the camera here is equally exceptional, expertly conveying a snowy, icy suburbia that mimics the emotions of many characters within the town. Lonergan knows that such delicate, at times emotionally challenging material rises and falls on the believability of the performance and the writing. Some of the most memorable moments in the film start off playing silently with actors conveying a wealth of meaning through action and implied intention before the scene will blossom and explode with dialogue. Other times, the dialogue will drift slowly away, the memorable, but unobtrusive musical score from Toronto native Lesley Barber will slowly begin to swell, and the audience becomes fully immersed not in the details of a scene, but in the raw emotion of it.

Manchester by the Sea builds to no grand climax, but a much needed conversation between an uncle and his nephew in which both men come to an understanding about their lots in life. It harkens back to the conversation Mark Ruffalo and Laura Linney’s estranged siblings have at the end of Lonergan’s You Can Count on Me in the sense that the viewer wants to believe that things will be okay, but we’re still unsure what the future will bring for these characters. It’s as life affirming as something this painfully close to reality gets.