Sublimely modulated performances and a deeply felt sense of place highlight "Manchester by the Sea." Writer-director Kenneth Lonergan (2012's "Margaret") displays a keen interest in his characters' lives and their intricacy of emotions. These are not merely pawns to a script, but the kind of layered, well-observed people whom one could imagine existing once the movie proper is over. This is fortunate, because Lonergan is also one for authenticity above all else. He refuses Hollywood conventions and tidy narrative bows, drifting alongside his human figures while promising none of them the closure viewers have been preconditioned to expect. "Manchester by the Sea" takes its sweet time—some may think it is too slow and too meandering, and a tighter edit wouldn't be total sacrilege—but there is also something to be said for a filmmaker confident enough to allow his every scene to breathe without the constant worry of pushing his narrative forward.

When older brother Joe (Kyle Chandler) dies suddenly from congestive heart failure, Boston-based handyman Lee Chandler (Casey Affleck) returns to his blustery New England hometown of Manchester-by-the-Sea to plan the funeral and stay with Joe's 16-year-old son Patrick (Lucas Hedges). When Patrick was younger, he and Uncle Lee were close buddies. In more recent years, they have drifted apart, the guilt Lee feels over a devastating loss in his past pulling him away from his family and loved ones. When the reading of Joe's will reveals his request for his brother to be Patrick's legal guardian, Lee finds himself questioning his ability to care for his nephew. For a man facing depression and the inability to come to terms with tragedy, he is going to have to make some tough decisions if he hopes to be there for Patrick as Joe wanted.

Weaving in and out of memories (sometimes in the same scene), "Manchester by the Sea" unobtrusively uses flashbacks as a way to inform Lee's present. His is a fully fleshed-out, three-dimensional protagonist, a tortured soul whose bottled-up feelings 95% of the time have left him with a short fuse the other 5%. Casey Affleck (2014's "Interstellar") is terrific in a complex, largely internal part, the one from whose point-of-view most of the picture takes place. As Patrick, a teenage boy juggling two girlfriends and the loss of the only parent in his life, Lucas Hedges (2012's "Moonrise Kingdom") holds his own while feeling entirely like a real kid. Hedges poignantly portrays the stages of grief Patrick is going through; when his ultimate emotional release comes, shortly after the funeral, it feels exceptionally authentic. As Lee's ex-wife Randi, Michelle Williams (2013's "Oz the Great and Powerful") paints a staggering portrait of a woman in turmoil. While she has managed to rebuild a semblance of a normal life, she, like Lee, may never be able to accept the magnitude of their shared loss. A late scene where Randi attempts to break through to Lee and forge a new friendship is the most affecting in the film, performed with a raw, riveting conviction by Affleck and Williams.

"Manchester by the Sea" dawdles from time to time in its pacing, and the lack of an arc for Lee proves uncompromising to the depths of his pain, if not wholly satisfying. A flashback involving the teen Patrick interacting with his dad also would have been welcome, helping to show the immensity of what is now gone from his life (as is, all flashbacks are reserved for his younger self, played by Peter Steve Harris). What has found its way into the final 135-minute version, though, is something to be proud of for all involved. Cinematographer Jody Lee Lipes (2015's "Trainwreck") turns the chilly, oft-gray seaside setting of Manchester into its own character of prominence—each scene is full of so many area-specific details it is amazing Lonergan didn't grow up in this community—while the writer-director is consistently attune to the natural ebbs and flows of everyday living. "Manchester by the Sea" finds the truth in each new moment even as the viewer longs for signs of hope that may never come.