Ben is Back, the father-son collaboration between writer-director Peter Hedges and actor son Lucas Hedges, plays out like a paperback page-turner with an inevitable conclusion. That the elder Hedges mostly succeeds in obscuring the histories of these characters and therefore where their paths will ultimately lead is a proverbial feather in his cap, the strongly-acted drama slinking suspiciously in narrative shadows in its earlier parts, leaving a trail of breadcrumbs that we intrinsically know lead nowhere good. As Hedge’s script unspools the mystery behind Ben and his being back, the thriller-tinged drama loses a touch of its suspect pull, relying strictly on emboldened performances to see the journey through. The experience is far from pleasant.

Airdropping us into the dust of some rather unsettled family trauma, Ben is Back opens when the oldest brother (Hedges) of a blended home unexpectedly returns home for Christmas. But all is certainly not right. Bruises – physical and emotional – hang in the air like the musk of mistletoe. Before he’s even uttered a word, Hedges reveals Ben is not to be trusted, his prying at shuttered windows and bursts of frustration when he can’t get in suggesting a none-too-stable lad reeking of desperation. Drugs are undoubtedly a cause for concern. Returning from church, Ben’s family cycles through a mix of emotions spying the ejected child sitting on their porch – elation, suspicion, excitement, a hint of terror – but that doesn’t stop his mom Holly (Julia Roberts) from racing to her first-born and embracing him with arms wide open. ’Tis a Christmas miracle, Ben’s backness, but one that won’t last long.

Despite her initial joy that her son will be joining them for that most festive of holidays, Holly steels herself against Ben’s charming ways, laying down a stern set of rules to keep her addict son in line during his 24-hour stint away from his designated sober living facility. He must submit to a piss test immediately. Doors must be left open and unlocked at all times. He is never to leave her sight. Even still, husband Neal (Courtney B. Vance) and daughter Ivy (Kathryn Newton) don’t think Ben’s jubilant little getaway is a good idea, pushing for his immediate return to constant professional supervision. Looking on, we’re left in a state of dazed wonder, guessing at what horrors Ben has already put his rightfully suspicious family through and the senior Hedges does a great job of amplifying this tension and putting his audience awkwardly in the middle of it all like a dinner guest trapped in a family pow-wow gone horribly awry.

The script (also from Hedges) can be part edifying, part frustrating, its methodology of slowly peeling back the characters’ pasts makes for engaging storytelling sure to keep audiences guessing, leaning forward into the screen, teetering on the edge of their seats, and genuinely curious as to where this is all heading. But there’s one too many monologues about past transgressions that the film gets bogged down in in its later bits, which causes the film to teeter into tell-don’t-show territory it seemingly can’t help but include. As Ben recounts the laundry list of wrongs that haunt his now-sober mind it feels like we’re only seeing one element of a much more complex equation and though it affords Hedges the range to Act with a capital A, it can feel at times a little overtly showy.

Thankfully the performances, particularly that of Hedges (the actor) and Roberts, milk every ounce of powder they can from the written word, delivering two almost-knockout turns as a mother-son duo who perform a twisted Christmas miracle (a rescue mission which further turns the emotinal knife) before the sun rises. Hedges adds yet another somber, sobering performance to a resume that already includes challenging work in Manchester by the Sea, Lady Bird, and Boy Erased. The 21-year-old Oscar-nominated actor has a capacity to go to some rather dark places but acting in front of his dad’s lens, he grapples with his most unsavory material yet. Ben is a complexly written character, with much the same virtues as Jesse Pinkman – he’s lovable for his innocent-enough smile and earnest adoration of kids and animals – but with temptation and trauma lurking spring-loaded around every corner, it’s hard to not chalk him up to a lost cause.

After years playing America’s girl next door, Julia Roberts has cemented herself as an actress of real dramatic worth and here balances a take-no-prisoners fierceness in with an unwavering maternal protectiveness – the result a difficult display of conflicting emotions. She’s great as a victim of circumstance unwilling to give up on her shameful son or give up when the going gets tough. The two performers share undeniable familial chemistry, which makes the most difficult portions of Ben is Back all the harder to swallow, like when Holly drags Ben to a graveyard, forcing him to pick out his final resting place, seeing that he’ll be in the ground “sooner rather than later.”

Between this cheery graveyard visit, an emotionally urgent, then kinda funny, then uber-depressing drop-in at an NA Meeting, and all the deeply troubling moral dilemmas where both Ben and Holly make some extremely questionable decisions, Ben is Back is a film wallpapered with depressing melancholy. Though suspenseful and strongly-performed, Hedge’s film is quite the opposite of a fun time at the theater, casting a spell of dejection and unease that may leaves audiences feeling, for lack of a better phrase, pretty bummed out.

Hedges (the writer-director) does a fine job of leaving clues of where everything is going spread throughout the picture, telling us one thing and showing us another, and holding us accountable when we – much like Ben’s mom Holly – overlook what we’ve been told. When we foolishly let optimism take hold, he’s there to pounce. Don’t be fooled: this is not a story of holiday redemption. This is not a cheery trip to the theater. In all honesty, this is one of the darkest, most forlorn dramas to take place over the course of Christmas, its misplaced hopefulness a coal-colored stain with the surefire potential to stick its melancholia on you like a tree ornament. Probably not the family movie you want to choose this holiday season.

CONCLUSION: ‘Ben is Back’ takes a different approach to an emotionally turbulent story of addiction and deception, figuring a suspense-driven framework that keeps the audience engaged and involved even as the film pivots towards increasingly depressing (and predictable) territory. Both Lucas Hedges and Julia Roberts are afforded the opportunity to dig into the characters and let their particular talents shine and are sure to leave you pretty darn sad for having watched.