Writer/director (and occasional actor) Kenneth Lonergan has an ear for dialogue and the proven ability to transfer the way in which people speak and interact with each other from the page to the screen. It was vividly on display in his 2000 film You Can Count On Me, for which he received an Oscar nomination.

Everything you’ve heard about Lonergan’s latest, Manchester By The Sea (Amazon Studios), which is already racking up awards and nominations, is true. Devastating, raw and real, the film features searing performances by Casey Affleck, Michelle Williams and Lucas Hedges.

Manchester By The Sea weaves back and forth from the present to the past, in long and short sequences. In the present, Lee (Affleck giving the performance of his career) works as a handyman/janitor at an apartment building near Boston in Quincy. He shovels snow in the winter, fixes leaky sinks and so on. He leads an almost monk-like existence in his basement apartment, although he has a tendency to drink too much at the neighborhood tap and get into fights.

The death of Lee’s older brother Joe (Kyle Chandler) in seaside Manchester, although not unexpected (he had been living with congestive heart failure for some time), still deals a blow to the younger brother. The brothers had been through a lot together, including the end of Joe’s marriage to alcoholic Elise (Gretchen Mol), the mother of Joe’s son Patrick (Hedges).

The brothers were also as much comfort to each other as they could possibly be following an unthinkable tragedy that struck Lee, his wife Randi and their three young children. It is this horrifying event that both dissolves Lee’s marriage and leads him to move more than an hour south to the Boston area. Now Lee is forced to return to Manchester to not only take care of the arrangements for Joe’s funeral, but to tend to other matters. Among those matters is a meeting with Wes (Josh Hamilton), Joe’s lawyer, who informs Lee that he was named Patrick’s guardian in Joe’s will, something of which he was previously unaware.

Patrick, who has lived in Manchester his whole life, has no interest in relocating. Because of this, and the fact that he’s a teenager with raging hormones (and two girlfriends), an active social, musical and sports circle, Patrick is constantly butting heads with Lee. To add insult to injury, Randi (who has since remarried) re-enters Lee’s life. The scenes between Lee and Randi, both pre- and post-tragedy, are the stuff of acting legend, with both performances achieving an aching authenticity.

Manchester By The Sea is heavy duty and unflinching. Don’t take your seat in the theater without a pocketful of tissues. Nevertheless, Lonergan finds ways to incorporate humorous touches throughout that allow his characters, as well as the audience, to breathe just a little easier.