If you have to watch one of 2018's two dramas about the parent of a teen drug addict played by one of the young hot It Boys who co-starred in Lady Bird - and I assure you that you don't, but let's say that you have to - I guess the least you can say is that Ben Is Back is much more of a functional object than Beautiful Boy. The two films are kind of exact opposites, given that they're also basically clones of each other: whereas Beautiful Boy was a chronologically promiscuous tale of several years in the life of a father trying to do whatever it takes to keep his son alive, shifting back and forth with the caprice of memory, Ben Is Back concerns just about 22 hours in the relationship between Holly Burns (Julia Roberts) and her teenage son Ben (Lucas Hedges). The latter has been in rehab for several months, getting his heroin addiction under control, and then he shows up quite unannounced and unexpected one morning a short while before Christmas, the night of the big church Christmas pageant for Holly's  children by her second marriage, Lacey (Mia Fowler) and Liam (Jakari Fraser). Holly is overjoyed, and her daughter, Ben's full sister Ivy (Kathtyn Newton),* is extremely disdainful and dubious, and so is Holly's current husband Neal (Courtney B. Vance). And this sets the stage for an extremely tense family Christmas, in which Ben's attempts to confront his past mistakes, Ivy and Neal's disinterest in forgiving him or even necessarily in seeing his face, and Holly's manic indulgence and the clear implication that her own incapacity to think of long-term consequences of words and actions has rubbed off on her son all come into conflict with each other.

Having thus set the stage, the film actually does none of that. Instead, Holly and Ben go looking for the family dog, which may have been kidnapped by the drug dealers that Ben screwed over back when he was using. Along the way, Holly is introduced to all the dark, grimy underbelly of her chokingly classy suburban town, learning just how wanton and desperate human lives in the gutter can be.

This is all very dumb. Whatever value the film has a study of the strained relationship between an addict and a mercurial parent, it does not survive the mid-film shift into the hunt for the dog. And even then, the hunt for the dog isn't nearly the best version of itself, whatever that might look like. Hilariously overwrought kitsch is never too very far away from the movie, but it grows actively campy in the glumly long second half, when it turns into an endless variation on the same conversation, in which Holly sternly asserts that she shall go with Ben into the NA meeting/shady convenience store/crack house/druglord's hideout, Ben sweatily asking her not to, and then her being aghast at what she sees. More fundamentally, the dog quest functions rather transparently as a way for writer-director Peter Hedges (Lucas's dad) to avoid having to do any genuinely hard work with either of his main characters. It externalises the film's conflict, not so much reflecting the internal conflicts of the first half as burying them beneath a simple, trite story that could function with just about any backstory for the two characters.

That being said, it's not at all the case that Ben Is Back was on the right track before it went so phenomenally bad. The first half also basically consists of just one scene being repeated over and over again: Holly snarling with tight-mouthed fury that Ben had better not fuck up, Ben sweatily promsing that he won't fuck up, Neal or Ivy suggesting that he probably will fuck up, and Holly screaming at them for being small-minded bigots. And while that scene at least has the benefit of being oriented around the characters, it's not actually any more interesting than the tedious dog material. Nor, frankly, is it all that much less kitschy. Holly is a very redundant, all-or-nothing sort of character, and Hedges père has apparently encouraged Roberts to lean into this as far as possible, turning every one of her line readings into an exercise in straining her face so much that it looks like her skull is going to pop out of her flesh.

This is no slam against Roberts, who somehow manages to turn this dubiously-imagined, shrill character into a pretty impressive achievement of screen acting - her best work since Closer all the way back in 2004, I'd say, despite all the problems that the film throws at her. There's a feeling of helpless terror that comes through Roberts's acting that I'm sure the film thinks is there in the script, though I'm not at all sure that it's the case. However it happened, her performance of Holly forces the character to be genuinely interesting and emotionally complex: operating out of a sense of love that she uses to adopt a willful ignorance about her son and the world, plus just enough of the prim, clipped cadences of a suburban bourgeois that we can never be entirely sure how much of her behavior is motivated solely by a desire to avoid scandalising the neighbors.

Whatever value the film has, it has thanks almost exclusively to Roberts, and it knows it. One of the first things that happens is a shot of her beaming that legendary Julia Roberts smile out into the world (the first image we see of a human in the movie, in fact), and that sets up anything good to follow: when the film works, it works in the tension between that smile and the dark, brittle exhaustion she's hiding behind it. Lucas Hedges is at least fine, though there's nothing very interesting or surprising in his performance. He's almost completely reactive, which doesn't help, though at least he looks convincingly distressed whenever he's confronted with the possibility of using drugs.

Outside of these two performances, and really just the one performance if we want to be terribly strict about it, the film has absolutely nothing to offer: the rest of the cast are ciphers, written as mechanical obstacles rather than humans, the film's predictability wrecks any tension or momentum that might come out of the 24-hour conceit, and it looks so helplessly bland that I can't even think of anything to say. It's banal Oscarbait with only the most clichéd observations about drug addiction or being a neurotic controlling mother, and Roberts's terrific acting is only enough to make that tolerable, not enough to make it work.

*Confessing my bias: after I noticed the "Holly and Ivy" joke, I turned on the film hard enough that I don't think it possibly could have ever won me back.