Starring Casey Affleck. Rated 14A

Without even knowing anything about Casey Affleck’s Lee Chandler, a low-wage janitor in a forlorn quarter of Boston, we’re sure that when he stops shovelling snow to take a phone call the news is not good.

Dependable at his work and lousy with people, Lee is from the old fishing town of Manchester. Like its gritty namesake across the Atlantic, the town is struggling to find a future to go with its deep history. Same goes for Lee, forced to return by the sudden demise of his beloved older brother, Joe, played in flashbacks by Kyle Chandler (no relation). More visits to the past tease out Lee’s own troubled story; something big has estranged him from his ex-wife (Michelle Williams), but writer-director Kenneth Lonergan is appropriately stingy with the information, making us explore the entrenched personalities to understand their strengths and weaknesses.

Clearly, Lee has an abiding attachment to his brother’s son, Patrick, now 16 and played by lanky young Wes Anderson veteran Lucas Hedges. The kid is actually too involved with hockey, playing in a band, and fielding multiple girlfriends to be completely thrown by his dad’s not unexpected death. (His mother, played by Gret­chen Mol, is mostly out of the picture.) But Patrick is willing to show his vulnerable side to his taciturn uncle.

As with his custodial penance, Lee is better at the logistical side of parenting than with its emotional demands. But Patrick is the one person who can bring him out of his shell, and he’s also the agent of change to turn a determinedly grief-stricken tale to one leavened by humour and kind behaviour in its second hour. Having spent more time on plays than on his own movies (Margaret and the award-winning You Can Count on Me), the director gives all his characters the dignity of space, supported by sparely used classical music. For viewers who like their humanism served raw, and plenty of it, this is one of the finest and most satisfying movies of the year.