Setting a tone of sweet quirkiness from the opening scene — complete with a Randy Newman–style clarinet-and-piano soundtrack — Roofman indicates right from the get-go that it’s offering nothing but pleasant comedy hijinks. The film is drawing on an eccentric true-crime case involving a divorced Army veteran in North Carolina named Jeffrey Manchester (Channing Tatum) who finds he can’t fit into regular jobs in civilian life. So in order to make money to support his children, he begins a series of burglaries of fast-food restaurants, especially favoring McDonald’s. He always breaks in through the roof, hence the nickname “Roofman.” And he’s noted everywhere for his extreme consideration and politeness to frightened employees as he knocks over the place.

“Just a real nice guy,” they tend to say afterward.

Jeff’s voice-over narration says we might be wondering how many McDonald’s you have to burglarize before you’re living a comfortable middle-class life that allows you to buy your daughter quality presents for her birthday. “Forty-five,” he tells us, as we see the spacious new house in a suburban neighborhood where his wife and daughters now live. That’s how many. Good to know.

But the police finally catch up to Jeff at that very birthday party for his daughter where, at last, he gives her the bike she wanted. The house is wildly overdecorated in an all-pink theme, with lots of kids and parents there bearing gifts, when Jeff has to make a run for it, trailing balloons and streamers. His daughter watches him get tackled and cuffed.

Once Jeff’s in prison and sentenced to an absurdly extreme forty-five years behind bars, his wife cuts off all contact between him and his children.

Hmm. Not so pleasant, some of these hijinks. And in fact, the longer you watch the movie, the more you wonder what the hell director Derek Cianfrance (Blue Valentine, The Place Beyond the Pines) is trying to do. The second act gets even stranger as the pace of the film slows to a crawl in order to represent, in excruciating detail, how Jeff escapes from prison, how he sets up a hideout within a hollow protrusion in one of the walls of a Toys ‘R’ Us, and how he meets a sweet-natured employee at the store, Leigh Wainscott (Kirsten Dunst). He begins a romance with her that soon draws him into a sweet paternal relationship with her daughters. But now Jeff has a second family life that can’t end much better than the first one did, because the longer he hangs around, the more certain it is that he’ll get caught and sent back to prison.

The dramatic heaviness of the situation overtakes the narrative, featuring Jeff in several woeful scenes crying large, drippy tears. Channing Tatum is given quite a workout as an actor, going from comic pratfalls to weeping in despair to oddly threatening scenes when Jeff’s lack of impulse control leads to a head punch that puts someone in the hospital, dangerous driving with Leigh and her kids in the car, and long-held shots of Jeff suddenly looking like a cold-eyed hulk, not “just a real nice guy.”

It’s weird, because overall the film seems set on the nice-guy angle, but the more it hints at other aspects of Jeff, the more you wonder why it doesn’t delve into them. What exactly was Jeff’s experience in the Eighty-Second Airborne Division that made him so unsuited to civilian life? What is it (as if we didn’t know) about regular American life that makes it so hard to navigate? Especially given Jeff’s extraordinarily handy skills that facilitate his burglaries, his prison breakout, and his cozy life for several months at Toys ‘R’ Us. Not to mention his unfailing ability to charm people that would seemingly set him up in any sales job in the country.

It’s noteworthy that Jeff’s old Army buddy Steve (LaKeith Stanfield) has also set himself up in a lucrative criminal enterprise. He charges an exorbitant fee to create a completely new identity for Jeff, complete with new ID card, passport, and an extensive made-up biography that will allow him to flee the country. If only Jeff would leave.

The material just isn’t a good fit for the heartwarming holiday-TV-movie tone set by Cianfrance, who also wrote the screenplay with Kirt Gunn. It’s even got a Christmas sequence near the end that’s the grimmest part of the film, anything but holly-jolly. Roofman might’ve worked much better if Craig Gillespie of I, Tonya fame had taken it on. Gillespie can get black-comic hilarity out of very rough-edged eccentric crime narratives and knows how to look at heartland-of-America madness without flinching, while still somehow delighting you.

In its theatrical release, Roofman was intended as “counterprogramming” for the other mainstream studio movie, Tron: Ares. Apparently the logic was that while the men watched the action-oriented sci-fi franchise reboot, all the women would line up for the movie offering hunky Channing Tatum and a central romance. Which just shows you the kind of complex thinking that goes on in the entertainment industry. As it turns out, neither film is doing especially well, and more men than women are seeing Roofman.

It’s too bad that ultimately Roofman crawls and palls, because the cast is excellent. Tatum is quite versatile and notably good at comedy, as we’ve seen in such movies as Deadpool & Wolverine, Magic Mike, and Hail Caesar! Stanfield (Atlanta, Sorry to Bother You) is always terrific, and it’s saddening to see him relegated to small supporting roles like this one. The riotous Juno Temple of Ted Lasso is in an even smaller, more depressing role as Steve’s tolerant girlfriend.

As for Kirsten Dunst, she’s both a great actor and an adorable personality. Her Leigh character is a dedicated Christian, and Dunst portrays her with such glowing sweetness, you can believe in her belief. Every time she deals firmly but kindly with her mean Toys ‘R’ Us boss (Peter Dinklage) or sings in the church choir, swaying back and forth in time with some appalling modern gospel song sung badly by her pastor (Ben Mendelsohn), you love her more.

After emotionally taxing performances in the heavyweight dramas Civil War and The Power of the Dog, Dunst wanted a lighter role, which is why she opted for this mid-budget fare with romantic-comedy elements. As she put it in an interview, “It’s the type of movie you wanna take your family to over the holidays.”

So there you have it — direct testimony that writer-director Cianfrance really meant to make an unambiguously heartwarming movie suitable for holiday viewing. And yet Roofman is really not that at all. Christmas at the Cianfrance residence must be pretty harrowing.