The relationship between fathers and sons is closely observed in this low-key family drama set in Northern Ireland. It broaches the difficult subject of preparing for bereavement while protecting the innocent.

It's a sad fact that the person who will suffer this loss is a four-year-old boy whose dad, dying of cancer in his mid-30s, has only months to live. John (James Norton) has come to terms with the brutal reality of his imminent death, and is now engaged in the practicalities of planning for his son's future. He must find a new family for his wee child, Michael (Daniel Lamont), who will soon be alone in the world.

Michael's mother left, breaking off all contact when he was just a few months old. There are no relatives around who might naturally take over Michael's upbringing, leaving it to John and social security to find the boy a new family when the time comes.

It is not always easy to watch the travails of this family of two, though the director Uberto Pasolini is restrained about their plight and the subtle original music by Andrew Simon McAllister has a light touch. Much rests on Norton's performance. The English actor, whom some say may be the next James Bond, is here a battened-down single dad who washes windows for a living and cares deeply about what the future holds for his son.

From the attractive distancing effect of the montage of windows framing other people's lives, washing windows can be read as a metaphor for John's place in the world. On the outside, an observer of the way others conduct their lives in the privacy of their homes, someone who has been peripheral and must now move on.

Yet this is John's story. He has been a good father. Michael has his tip-up truck, a plastic model dinosaur, a pet, and his father's undivided attention, the signs of engaged parenting, though the boy remains a quiet presence throughout and there is little shown of his character.

We learn that, as the son of a long-distance lorry driver who lived in foster homes from the age of four, Michael had a poor start in life. Whatever the swallow tatts on his neck and the bold, ornate inkwork on his forearms signify, the only thing that matters for John now is that Michael has a loving new family to go to when he passes on.

Based on Pasolini's screenplay and inspired by real events, the narrative quest is finding the right fit for Michael.

As father and son meet with the people who have applied for adoption, at these assessment sessions they are accompanied by Shona (Eileen O'Higgins), their sweet-natured case worker.

Prospective parents come in many shapes and sizes, familiar social types we may either wish to cringe at or celebrate.

In between these interviews, John does the rounds at work. Cleaning the windows of homes of material comfort, where children's rooms are packed with toys, and family pets have the run of the backyard.

As luck would have it, I happened to see Pasolini's last directorial release, Still Life, in 2013, with Eddie Marson in the role of a council worker who takes on the responsibility of locating the next of kin of people who have died intestate.

It was an odd one, but showed a similar humanity and generosity of spirit that is operating here.

Uberto Pasolini is best known in the industry as a producer, his credits including the wildly successful comedy, The Full Monty.

He is not, by the by, any relation of the celebrated Italian filmmaker, Pier Paolo Pasolini, but he is related to another equally celebrated filmmaker, Luchino Visconti.

This sad story is somewhat unrelenting but there is a certain wry humour in the portraits of the various singles and couples who have put their hands up to adopt a child, even the most obnoxious. Like a childless couple who show why they should remain that way.

Then, before the final big reveal, father and son walk up the stairs and along a corridor towards Michael's new home and journey's end.

After all the restraint, here comes one last shot that gets you where you live.