It's a little early to be talking up Christmas movies, I know, but "The Baltimorons" could become a seasonal classic, so let's discuss. The picture stars no one you're likely to have encountered at the local megaplex before, and it was probably made for the Hollywood equivalent of a handful of subway tokens. But the movie gets over on pure charm, and if you take the time to see it now, it can inhabit your heart until this year's Yuletide actually arrives.

The story unfolds with a sweet simplicity, like a tale being told over a crackling pub fire, let's say. We follow the characters around the wintry streets of Baltimore, where wreaths twinkle and the cold bites, as Christmas Eve slowly fades into Christmas morning, bringing with it holiday talk of soft-shell crabs and sweet potato casseroles and ushering in life-shifting changes that none of the people we're watching could possibly anticipate.

Foremost among these characters is a man named Cliff Cashen (Michael Strassner, who wrote the movie with director Jay Duplass). Cliff labors at some piffling job at the moment — he's a mortgage broker — but that's a front: In his soul he's a standup comic, a man who comes fully alive only onstage, doing sketches and improv. Not too long ago, he was part of a popular local comedy troupe — something along the lines of L.A.'s Groundlings or New York's Upright Citizens Brigade, presumably — but the late-night club grind turned him into an alcoholic. Then something dumb happened and he lost his comedy gig and his life fell apart. Things have gotten a little better since then — he now lives with his fiancee, Brittany (Olivia Luccardi), and she's a sweetheart. But Cliff, off the sauce and comedy, too, is quietly miserable.

The story is launched with a minor accident — Cliff trips on something and chips one of his front teeth. Despite it being Christmas Eve, he manages to find a dentist who's open. Her name is Didi (Liz Larsen), and she of course has a story of her own: self-sufficient divorcee, mother of one grown daughter, not a lot of illusions left. As she pokes around in Cliff's messed-up mouth, these two slowly start relating to one another — a development so subtly portrayed by Duplass and his stars that it's hard to pinpoint exactly where off-the-cuff cordiality edges over into something ... more interesting.

Probably nobody would pick Cliff and Didi as a natural match. He appears to be drifting through the back half of his thirties, while she would seem to be situated on one or another side of 50. This is a plot setup primed for cornball overkill — for Didi to find a brief new lease on life with a younger man, for Cliff to acquire a Life Lesson or two from a seasoned older woman. Let us all bow deeply in the direction of Duplass and Strassner for not pooping out a script like that.

What they've given us instead is a portrait of a couple in which one partner finds herself and pretty much everyone around her — family, friends, small children, possibly even puppies and kittens — lifted up by the unconquerable optimism and total engagement of the other. Cliff, with his burly body, out-of-date hair-and-beard combo, and schlumpy snow-beanie, finds excitement in everything. Even a simple visit to Didi's tastefully furnished house is an event. ("Wow, you must have good credit," he tells her, looking around.) And while there's no real reason for him and Didi to stick together as the night lengthens, Cliff doesn't need one. ("'Cause we're havin' fun!" he says.)

The movie has two remarkable scenes. In one, Cliff has brought Didi to a pop-up comedy show at an auto body shop (telling her that any snacks on offer will probably consist of "jellybeans and vodka"). There he informs the audience, which is familiar with his work, that he intends to reprise one of his trickiest bits of improv. However, he needs a second person to take part as well — and the only volunteer turns out to be Didi, who knows nothing about performing but is game nevertheless. What follows is like a documentary examination of the ebb and flow of comedic rhythms — and the flop-sweat terror that can bring a set crashing down at any moment. It's like dying a little bit onstage yourself.

The other memorable scene is simpler — a penetrating close-up of Cliff and Didi's faces as they slow-dance to Lia Booth's recording of "Someone to Watch Over Me," backed by the Jordan Seigel Trio. (Seigel also composed and performed the film's richly harmonic score, which is like an extended tribute to the work of the late jazz-pop pianist Vince Guaraldi.)

Cliff and Didi's coming together is never a foregone conclusion — Didi more than once teeters on the edge of pulling away and returning to her pre-Cliff existence. But what can you do with a guy like this when he's standing there, oblivious to all other possibilities, asking questions like, "You wanna keep this thing goin'?" Well ... you think it over.