Pain is supposed to be a positive thing.

And no, I’m not just talking about s & m fanatics, tory MP’s and brexiters.

But pain does let us know when something is wrong, so we can at least begin to look for a way to heal ourselves.

Without this, we’d all be in the ground a whole lot quicker than we’d hoped.

What happens when you experience something so painful that you know you’ll never heal from this though?

It’s not an easy thing to talk about, and yet that’s just what writer and director Kenneth Lonergan has managed in his brilliant new film Manchester By The Sea.

Lee is a lonely and humourless man.

By day he works as a handyman of sorts; cleaning out drains, fixing showers and unblocking toilets in a residential apartment block.

By night he drinks on his own at bars, closing down conversations that might turn his way before looking to start a fight with anyone he can provoke into throwing their fists.

It’s not much of an existence, and it’s not clear why he chooses such an empty, punishing kind of life for himself either.

But when Lee receives some bad news about his family, he puts his so-called life to one side and heads back to his home town to repay a debt to his older brother.

Helping himself, however, is going to be a lot harder.

It’s tricky to talk about Manchester By The Sea without spoiling the plot, which slowly unfolds through flashbacks as our anti-hero battles with his own very personal demons.

So I won’t.

But the themes of grief and our struggle to find a way to live with this have never been more brilliantly captured than in Manchester By The Sea.

Casey Affleck is withdrawn, restrained and quietly great as the broken-down soul Lee, slowly drowning in an ocean of guilt and suffering that he cannot see a way out of.

Beyond help, all he can do is exist as he wrestles with his thoughts and his past.

And yet, despite choosing to explore something so dark, so intense and so emotive, Lonergan has found a way to inject life and laughter and even love into his film.

It’s not the love you’d expect to see in a Hollywood movie, and it’s not the love you hope for yourself or the ones you care about.

But it is love nonetheless, a deeper kind if you will, and it feels all the more real because of this.

The supporting cast lead by Michelle Williams, Kyle Chandler and Lucas Hedges excel in creating a canvas for Manchester By The Sea’s leading man, particularly Williams’ heart-breaking climactic scene with Affleck.

But this film is all about Casey Affleck’s painfully beautiful performance, one that will probably add another Oscar to his family’s collection of awards.

Which will hopefully be a similarly painful experience for his older brother.

Jonathan Campbell