“To get on in this life, there are things you have to ignore,” utters housewife Eileen in Small Things Like These. It could have been Ireland’s national motto for a century.

This story, about the rot at the heart of the Catholic Church and the state-sanctioned abuse of women and children within the Magdalene laundries, unfolds quietly, witnessing how individuals and communities ignored the cruelties being inflicted. A note at the end this adaptation of Claire Keegan’s novels acts as a stark reminder of the sum of these small, ignored things: the film is dedicated to the more than 56,000 young women who were sent to Magdalene institutions for “penance and rehabilitation” between the years 1922 and 1996, and the children who were taken from them.

Adapted by Enda Walsh and directed by Belgian director Tim Mielants, Cillian Murphy stars as Bill, a quiet family man who works hard providing coal and fuel for the townspeople of a small, God-fearing community in '80s New Ross.

Bill is taciturn but kind, giving his spare change to local children when he knows their family is struggling, letting customers build up large tabs, and treating his workers well. This kindness earns him both respect and suspicion – a suspicion based in class dynamics. While Bill was born to an unwed teenage mother, he and his mother found sanctuary with a wealthy widow and landowner Mrs. Wilson (Michelle Fairley) who protected them both from the abject poverty, social stigma and Church control that so many others in their position would have faced.

Thanks to Mrs. Wilson’s kindness and support, Bill was able to build a successful business – but the circumstances of his birth and his proximity to wealth give him an outlier status in the small working-class town. Everyone in New Ross is focused on economic and social survival, and believe that the only way to endure is obeying the strict rules that control their movements and behaviour – norms that Bill breaks in small but noticed ways. Even his wife Eileen (Eileen Walsh) holds some baggage over Bill’s upbringing, believing that Mrs. Wilson’s wealth protected her from the limitations facing most Irish women and gave Bill unrealistic expectations about how free women could be. Fearful for the fate of their five daughters, Eileen subtly perpetuates internalised misogyny, judging other girls and women for not being “respectable”.

These fears for what could happen to her daughters if they step out of line are not unfounded. The harsh realities facing young women are viciously illuminated when Bill delivers coal to the local convent and discovers how the nuns are treating one of the girls there. His findings are horrifying, though not shocking to anyone with even the vaguest awareness of how Irish religious institutions treated “fallen women”.  This discovery awakens Bill’s own childhood trauma, which unfurls in flashbacks as we watch him grapple with guilt, fear and complicity in the present.

Cinematographer Frank van den Eeden’s work is exquisite, often following Bill as he walks through the New Ross, a place which emanates a sense of claustrophobic tension and surveillance – open your front door and the whole town will see and judge what you do. Despite being set over Christmas with some festive lights, there’s a drab, earthy mustard hue over everything, lingering like a bleak toxic fog. This atmosphere permeates through every interaction, all rigidly controlled by facades of politeness and fuelled by compliance – an obedience that the ferocious Sister Mary (a powerful and unnerving Emily Watson) plays on. Every word she utters is laced with unchallenged power and unspoken threats.

Walsh’s sparse use of dialogue allows the film to play with the unsaid, and it’s here that the performances prove impeccable. Murphy has portrayed a lot of quiet characters in his career, always managing to imbue them with a different tonality. Bill is no different, brimming with grief and desperation. Every action becomes heavy with meaning – a tapping foot, an averted gaze, the daily methodical cleaning of his soot-covered hands.

The flashbacks prove a little clumsy and an apparent reveal is telegraphed too clearly to have the emotional resonance it’s aiming for. That said, Small Things Like These's understated emotion, as well as the quiet unfolding of social realities and the questions it raises about power, control, morality and collective complicity are vital, with an elegant ending featuring a small but powerful moment of defiance that we should all cling on to.

• • In Cinemas now. Watch the trailer below: