The three saddest words we hear off the screen this year just might be, “Jesus, John Paul.”

Sarah Greene speaks them, playing a Dublin mother of four, in “Rosie,” a heartbreaking, underplayed and intensely gripping Roddy Doyle story about modern homelessness.

Greene is the title character. Rosie has spent all day, for days on end, running through her cell-phone minutes, trying to find a place for her, her toddler to tween kids and her kitchen-assistant partner, John Paul (Moe Dunford) to live.

And that line and the way Greene (of “Noble,” and TV’s “Penny Dreadful”) plays it is as wrenching as any anecdote from “Angela’s Ashes.” There is exhaustion, despair and just a touch of panic in her performance.

“Jesus, John Paul.”

She’s getting the kids dressed, every morning, feeding them and taking them to school in the under-sized minivan in which all their worldly belongings are packed. She’s not giving up her hope and determination, not letting the little ones — and her oldest, Kaley — see her desperation. She is not losing her temper.

But just at this moment she sees the juggled balls hitting the ground. In this instance, all her “My faults” and “I’m sorries” that get her through the day — with the kids, who whine, bounce off hotel beds when they have a room, off the walls of the van while they’re looking for a room, with the teachers she apologizes to about “late again” — hit her right in the face.

“Jesus, John Paul.”

In one of the great cities of Europe, with all the social safety nets a citizen of the modern European Union can expect, a lower middle class mother and her mate cannot provide the most basic shelter for themselves and their four children.

Doyle, a chronicler of modern working class Dublin without peer (“The Snapper,” “The Van,” “The Commitments”) taps into the irony of this most domestic of domestic tragedies.

And Greene becomes his muse, his vessel for making a statement about how close to the margins many of us are in a world where housing, in the control of what-the-market-will-bear landlords, is increasingly imperiled.

Dublin, like many cities, is pricing the lower ranks of the social order right out of their ability to survive there.

Greene gulps down the alarm in her voice when Rosie hears, from a hotel clerk, that Lady Gaga is in town for a show. She knows that hundreds of hotel rooms are now out of circulation for days, subsidies from the state be damned.

The calls are all the same — “I’m looking for a room for a few nights. There’s six of us.” One call after another, poker-faced pleas that cannot show the panic, the urgent need.

“That’s right. City Council Credit Card.”

One child is hyperactive, another plainly stressing out at Mom’s “We just moved house” explanations to one and all, hiding their eviction from the place that is now being sold, “too dear” in price to be within their price range.

The youngest is fully potty trained, but frazzled by all the driving, calling, moving in with garbage bags full of clothes.

“I need the toilet. I need the toilet now.”

“Ok. Right,” Mom says. And then a moment where we catch the lost look in her eyes, “Where’ll we go?”

The oldest girl Kayliegh (Ellie O’Halloran) dutifully does her homework, bottles up her gripes, embarrassment and disappointment and tries to not be a burden. That’s a lot to ask of a 13 year-old girl.

Director Paddy Breathnach, who gave us an early Brendan Gleeson triumph, “I Went Down,” doesn’t fussy up this simple tale. The camera is always on Rose, “Rosie,” as her kids turn fractious and another hotel patron in the same situation begs her to quiet her unruly son “or we’ll’ get trone out, like. And I’ve nowhere else, like.”

John Paul is low man on the totem pole at the restaurant, so he’s little help during the day — lunch break apartment and house hunting — getting a call where his family will be on his bus ride “home.”

“Remember when we used to think it’d be great to stay in a hotel?”

Doyle injects a little extra melodrama in the estranged relationship between Rosie and her mother. They’ve already worn out their welcome with every other family member and friend in Greater Dublin, but Grandma’s place could be out of the question.

Any parent will recognize the form childhood rebellion takes in a seven year-old, and a thirteen year-old. Anybody watching will fear for Rosie’s sanity as she has zero time to cope, no energy left for added drama, which children cannot help but provide.

And any film fan will appreciate seeing one of the great, subtle performances of the 2019 cinema, glorious work in the simplest and most dramatic role of them all — motherhood.

MPAA Rating: PG-13 for thematic material.

Cast: Sarah Greene, Moe Dunford, Ellie O’Halloran

Credits: Directed by Paddy Breathnach, script by Roddy Doyle. A Blue Fox Entertainment release.

Running time: 1:26