“Small Things Like These” is a slim book by an Irish writer, Claire Keegan, that tells the terrifying and true story of the abuses of the Magdalene laundries over centuries in the Emerald Isle. Now, “Small Things” is a movie. It is a meditation on suffering hiding in plain sight and an explanation of what must be ignored for life to keep calm and carry on. The evil at the edge of vision is what can make a mess of bright happiness.  

The Magdalene laundries were run for profit by religious orders and intended to punish women — frequently unmarried mothers — considered promiscuous. Most commonly, a mother’s baby was taken away at birth, and she was imprisoned in a convent. One research institute explains that “girls and women were imprisoned behind locked doors, barred or unreachable windows and high walls (oftentimes with broken glass cemented at the apex).”

The last of these institutions devoted to “penance and rehabilitation,” at North Dublin, closed only in 1996. It is now a memorial. In 2013, Ireland, after years of denying responsibility, apologized “unreservedly to all those women for the hurt that was done to them, and for any stigma they suffered, as a result of the time they spent in a Magdalene laundry.” Many of the women consigned to slavery behind convent walls died. Mass graves have been uncovered. 

“Small Things Like These,” set in 1985, tackles this history. Its protagonist is a humble hauler of coal, Bill Furlong, played with near-silent agony by Cillian Murphy. His words are few but his face is a canvas of forbearance and slow-motion outrage. Furlong is all too acquainted with gravity’s force — the world’s unremitting heaviness — as he schleps around New Ross in smudgy gray dawns streaked with rain. Christmas has rarely looked so dismal.

Delivering coal has enabled Furlong to live a roughly middle class life in Ireland’s southeast. He has a wife, Eileen (Eileen Walsh), and a brood of daughters who one day in the future might hope to meet the Celtic Tiger. His concerns center on gifts for the holiday and how long his back can hold up under the rocks he lugs. One day, though, he sees a screaming young woman manhandled into a convent by a nun. He is himself the son of an unmarried mother.

Furlong and his mother, though, had been taken in by a wealthy Protestant widow, sparing them the fate of a laundry. The girl, Sarah, whom he encounters has no such luck. Furlong arrives for a delivery one morning to discover her locked in the coal shed, more livestock than person. His glimpses in the convent disclose a site of misery staffed by pale girls with wounded eyes. He becomes inconveniently obsessed with a smothered scandal.

Furlong’s sympathy for Sarah leads to an extraordinary fireside chat with the convent’s chieftain, Mother Superior Sister Mary (Emily Winston). She dissembles and tells him that Sarah was locked in the shed by the other girls, and threatens — implicitly but unmistakably — the family’s future if Furlong says anything to the contrary. She speaks with the assurance of a crime boss and the authority of a medieval prelate with an envelope of cash.  

“Small Things” homes in on states of half-knowing. Furlong’s wife tells him that “if you want to get on in this life, there are things you have to ignore.” Another friend warns that the nuns “have their fingers in every pie.” Ms. Keegan asks in her book: “Why were the things that were closest so often the hardest to see?” She, and this movie, are interested in farsightedness in the same way that an ophthalmologist would be — blindness to the close at hand.

Furlong bears his own childhood scars, and “Small Things” postulates that injustice can be counteracted by a confederacy of the injured. Complicity is too much to the advantage of the whole and healthy. Furlong’s choice is whether to save one girl. The movie’s conundrum is how to address a network of crimes so sprawling that it infects every joy and taints every compromise. How to live and love in the knowledge of the horror next door?