On the surface, very little happens in this 47-page-long novella: a man accidentally closes a work file, he struggles to open a bottle of champagne, he worries his bus won't arrive, he tries to avoid mulling over a past relationship in his mind.

However, in the hands of Claire Keegan it becomes a bewitching, infuriating and fraught exploration of regret, misogyny and marriage.

So Late in the Day is Keegan’s fifth publication, and comes two years after the publication of her first novel, Small Things Like These, a critically lauded work – a big screen adaptation of which will be released next year, starring Cillian Murphy.

We meet Cathal, a typical Irish man working for the Arts Council, on what seems like a normal Friday. In the last few hours of work he suspiciously avoids looking at his phone and office chitchat. It is soon revealed that that day was due to be his wedding day, and he spends the novel combing through the deterioration of his relationship with his ex, Sabine.

Things start off well. They go on dates to art museums and shop together. However, it’s the novella’s finer, unspoken details that slowly paint another subterranean picture.

They’re the human things, the cues you notice instinctively, without words, captured beautifully by Keegan. How Cathal treats the couple’s cat Mathilde, his heart "lurching" when he can’t immediately find her inside the house, only to pick her up, notice how heavy she is and lock her out the back. How he clocks the way Sabine "bought freely", and bristles at having to spend €6 on cherries for a dessert she bakes him.

The meanness extends even to buying Sabine’s engagement ring, when Cathal brings her outside after being charged extra for resizing the ring, snapping, "Do you think I’m made of money?"

It’s easy to guess at Cathal’s motives for pursuing Sabine: companionship, a desire to control, a need to reach the milestones expected of him. However, there’s an all-too-familiar whiff of his actively disliking women, as they really are, how he notes that "she looked different without her makeup, going around in a tracksuit, sweating and lifting things and making him lift and move his own things, pushing back the furniture, the strain showing so clearly on her face."

The story was, after all, originally published in French under the title Misogynie.

But Keegan plumbs at something deeper. His assumption that Sabine would – must – want a child, too, hints at it. It’s there in an early line, a sense of "the tangle of human upsets and the knowledge of how everything must end".

It’s hard to shake the sense that Cathal is a man outrunning something by chasing something else, something he feels entitled to. What that might be should be down to the reader to decide for themselves.

Much like in her previous works, there are moments of heart-chilling cruelty. In this story, Cathal recalls watching as his 20-something year-old brother pulled the chair out from under their mother as she went to sit at the table, laughing afterwards along with their father. This incident, Keegan told The New Yorker, was autobiographical, an incident that stayed with her all her life. It’s no wonder, then, that it lingers painfully long after the reader finishes her novella.

It clearly haunts Cathal, too, who wonders "how he might have turned out if his father had been another type of man and had not laughed".

There is a glimmer of hope, however, for him, a single line that thrums with significance on the first reading, and reveals its true message on the second. It feels like it might be an olive branch from Keegan, a teacher leading by example, showing how easy it could be to walk back the generations of misogynistic assumptions, thoughts and narratives that she sees some Irish men absorbing. Whether that succeeds, however, is up to each reader.

Keegan is one of our best observers of social history, and her work is a masterclass in form and style. As noted, very little happens in this story, but this masterful story of small observations, precisely made and compellingly distilled, brings these moments so realistically, so finely, to life that they become the tense, emotional centres of the work. Much like in life, it’s the small innocuous moments of our days, our lives, that end up feeling the most important.

So Late in the Day is published by Faber