The story at the heart of Being Flynn—troubled young wannabe writer takes a job in a homeless shelter and one night comes face-to-face with the father he never knew—would seem hopelessly contrived if it weren’t true. The movie’s great achievement is that it so effectively captures the poetic grace of the 2004 book on which it’s based—Another Bullshit Night in Suck City: A Memoir, by Nick Flynn, who actually is an esteemed poet—without wobbling into mush. Equally welcome is the reminder it provides—for those who may have forgotten, or never known—of what an electrifying actor Robert De Niro can be when given a smart script and a densely complex character to portray.

The young Nick Flynn is played here by Paul Dano, a performer whose underwatery eyes and sense of smothered desperation suggest that he may be drowning—which in fact Nick is. It’s the late 1980s, and Nick, in his mid-twenties, has yet to amount to much. He feels he was meant to be a writer, but is reluctant to show anyone his work. His father, Jonathan (De Niro), claimed to be a writer—in fact, one of the greatest writers who ever lived, a genius—although no one ever saw his work, either. In any case, Jonathan’s gifts are a matter of hearsay: Nick has no clear memory of the man, who deserted his mother, Jody (Julianne Moore), when Nick was a small child. (“All my life,” says the now-grown son, “my father has been manifest as an absence.”) Nick wonders if he might have inherited some of the writing talent his father claimed to have. He’s also beginning to wonder, more darkly, if he has inherited his father’s penchant for heavy drinking.

We meet Jonathan before Nick does. We see that he’s barely getting by as a New York taxi driver, and that he’s a pompous, boozy fool who chooses to look upon his nose-diving life as “material” for the masterpiece he has never stopped writing—a book he calls The Button Man. Jonathan is an impossible case—blustery, violent, bigoted. He doesn’t make excuses for the many screw-ups in his life (he once did two years in prison for kiting checks); he simply ignores them, in order to concentrate more completely on his still-undemonstrated genius. De Niro is rigorous in depicting this shabby man’s worst characteristics without softening them; and he’s witheringly precise in conveying Jonathan’s sudden, unexpected flashes of insight and dismal self-awareness.  

When Jonathan is evicted from his cramped apartment after an unfortunate incident with a nail-studded baseball bat, he reaches out to his son for the first time in 18 years. They meet briefly, but Jonathan, unmoved by this improvised reunion, quickly fades back out into the wintry streets. Hungry for some meaning in his life, Nick takes a job at a homeless shelter. One evening, handing out bedding amid the nightly crush of down-and-out “clients,” he looks up to see his father—who has just lost his hack license and thus the taxi in which he had been sleeping—once again standing before him. “I would like a room for the evening,” the old man says, with his customary pointless panache.

Jonathan continues to spend his days, and many of his nights, on the streets. And as Nick tracks his aimless peregrinations, the movie affords us an unsparing view of the homeless life, with Jonathan begging cups of coffee at a diner, sleeping on benches and sidewalk hot-air vents, and crouching fearfully in the dark as young thugs prey on other homeless men nearby, and sometimes kill them. We know about this bleak urban existence, but we may no longer register its presence all around us. “My father is an invisible man,” Nick says, “in an invisible city.” 

Director Paul Weitz never milks this story for pathos, and De Niro even manages to leaven it with startling humor whenever Jonathan launches into one of his scabrous rants. Julianne Moore is typically deft as Jody, a single mother slowly reaching the end of her emotional resources; and there’s also a carefully veiled performance by Olivia Thirlby, as a shelter co-worker with whom Nick begins a tentative romance. The movie is more than an exercise in heartbreak, but it leaves us with little hope for its down-bound characters.  At one point, a fellow shelter employee named Joy (played by Lili Taylor—the real Nick Flynn’s wife) gives Nick an unvarnished appraisal of their jobs. “We catch ’em on the way down,” she says. “Next stop: the morgue.”  

Kurt Loder is a writer living in New York. His third book, a collection of film reviews called The Good, the Bad and the Godawful, is now available. Follow him on Twitter at kurt_loder.