Timothy Olyphant has a remarkable jaw. Tucked innocently into his neck or jutted out at a perturbed angle, the set of it communicates upwards of seventy-five percent of his acting in any scene he happens to be in.

Much hinges on this jaw in Hold On To Me Darling (at the Linda Gross Theater, through April 17), the new play from Kenneth Lonergan (This is Our Youth), an uneven meditation on the cultish and enfeebling nature of celebrity obsession. Mr. Olyphant plays Strings McCrane, “the third most successful crossover artist” in country music history, insists his toadying assistant/“best friend” (an earnest Keith Nobbs). The name of the play comes from one of Mr. McCrane’s most well-received songs, doing double service as the longing undercurrent of the play.

Strings has just lost his mother unexpectedly, a sharp-tongued and disapproving woman whose dream for her son was not the fame to which he has ascended from his small hometown in Tennessee, but rather a staid domestic life with a good, solid woman. Making a spiraling series of bad decisions, Strings decides to move home and find just such a woman to finally make his dead mother happy.

When the play first began, your correspondent worried that the constraints of a stage might prove too intimate for Mr. Olyphant’s big- and small-screen charm. He enters as a ham, overplaying hand gestures and straining his soft Southern accent to its limit in his dolefulness. He’s essentially blameless, however, as it turns out this kind of affectation is written into the character from the jump.

Strings has a goofiness and broadness to him, which is a tough comic act to pull off. Mr. Olyphant is much more at ease when irritated and unhappy, a familiar skin for the actor who played U.S. Marshal Raylan Givens for six seasons on Justified, a man whose crankiness seemed a part of his job description. His one-shouldered shrug pairs with an extension of the aforementioned jaw to create a gesture as natural as you please. It’s no less satisfying the third or hundredth time, which serves Mr. Olyphant, and the character, very well indeed. You can’t help but like the guy, even when he’s acting truly terribly.

And act terribly he does. Throughout the course of the play, Strings brings a newly gained love interest (Jenn Lyon) to his mother’s funeral, seduces his vulnerable distant cousin Essie (Adelaide Clemens), quits his multi-million dollar sci-fi film shoot, drags his ornery brother (C. J. Wilson) into buying a feed store to live the simple life, and generally makes a mess of things. He’s basically a large child who seems to genuinely regret his mistakes, but is incapable of learning from them. Mr. Lonergan would like to blame that on his celebrity status, but it is all too common an affliction even in mere mortals.

Ms. Lyon plays the ambitious Nancy, a sunny masseuse with designs on getting out of a stalled marriage and into a life of leisure. Lyon is a gifted comic actress with impeccable timing, hitting every beat with stride. She makes an art out of communicating something quite different with every lilting hunny, deployed about as frequently as you’d expect from a Southern gal.

C. J. Wilson is a natural as Strings’s brother Duke, delivering his frequent “Jesus Christ in [an unlikely location]” epithets as white noise to his sibling’s fancy predilections—like talking on the telephone. (Sample: “Jesus Christ in a downtown Memphis hair salon!”) The dialogue is easy and feels authentic to a small town; certainly it’s exaggerated for effect, but it’s not archetyped into Archie Bunker-land. When Strings expresses his sudden, idealistic, and naïve desire to work in the feed store, it prompts a procedural invective from Duke that is one of the funniest moments in the play: a step-by-step account of a day in that life that lays bare just how little thought Strings has given to real hard work. Wilson dryly delivers an impressive litany of all the food items Strings will be responsible for, punctuating each brand of dog chow or cat food like they’re nails in a coffin.

Kenneth Lonergan has a pedigree in film as well as theater, having directed and written You Can Count on Me, and his sensibility for a movie set is reflected in the excellent and near-magical staging by Walt Spangler. The set rotates 180 degrees from scene to scene, displaying entirely new set designs from a hotel room to a shabby house to the feed store, from the wallpapering down to end-tables. It’s impressive technical stuff.

The messaging of the play ultimately doesn’t demonstrate very much about celebrity that you couldn’t read in a thinkpiece from time to time if a Kardashian annoyed you that day: we create these heroes only to tear them down; we hold them up as role models when they’re just as petty and silly as the rest of us; we let them get away with their bad behavior because they deliver entertainment, both professionally and in the gossip rags. That’s not to say the play is unenjoyable, just not particularly deep.

It does get in the way of its fine cast, however, by forcing them through lines and scenes that tend to repeat themselves, given that lack of depth. There are only so many times we can watch Strings charm or growl his way out of a problem, but we’ll watch them over and over during the course of the three-hour play. Probably we only start excavating beyond the epidermis of this character in the final scene with his erstwhile father, which is lovely and difficult and then very firmly over. There’s not much here to hold on to—no Arthur Miller-style final, gasping catharsis here—but in the end you can’t begrudge the underworked material too much. Sometimes it’s nice just to watch actors be good at their jobs and not overthink things, which is doubtless not exactly what Mr. Lonergan intended.