Lee Chandler (Academy Award winner Casey Affleck) is a repair man in Quincy, Massachusetts. He lives alone in a one room flat. He spends his days shovelling snow away from paths and doing mundane maintenance jobs in apartments. His evenings are spent drinking, and occasionally fighting, alone. When he receives a call from George, a family friend, informing him that his brother Joe is gravely ill, he drives to Manchester By The Sea, his old hometown.

But he arrives too late. Joe has died, leaving a sixteen year old son Patrick (played by Lucas Hedges). Joe and Patrick’s mother have long been separated.

A few days later, at the reading of Joe’s will, Lee discovers that his brother intended for him to be Patricks’ guardian – a role Lee immediately rejects. Something terrible has happened in Lee’s past. He can’t bring himself to stay in Manchester By The Sea. He is a broken man. And his is a brokenness that will never heal.

As a movie, Manchester By The Sea inches slowly along. The writer/director Kenneth Lonergan (You Can Count On Me) is a successful playwright who is a master of compelling dialogue. And as a director he uses a series of flashbacks to reveal and then hide and then reveal various aspects of Lee's trauma. I knew Lonergan would eventually reveal the cause of the darkness that shapes Lee. But when he does reveal it, it is far worse than I could have expected. Even now, two days after seeing the film, I am still haunted by what I saw, by what Lee Chandler went through.

Manchester By The Sea is superbly written, brilliantly acted, painfully real, beautifully shot, and unflinchingly honest. It confirms in my mind that many, perhaps most, of us have a backstory that includes damage and trauma and guilt and shame. Some of our tales are too complicated to tell. Some of our shame is too painful to remember. Sometimes we are so broken as to be unrecognisable, even to ourselves. Sometimes we are offered a second chance, but we are too wounded to take it.

It is an exhausting and emotionally stretching film. But if we allow it to, it has the capacity to make us into better friends, and more honest neighbours.