It’s not easy to introduce a novel element in the well-traveled genre of coming-of-age films, but writer-director Megan Park turns the trick with her second feature, My Old Ass. In the film, Elliott Labrant (Maisy Stella) is scuffling through the last few weeks of summer working on her family’s cranberry farm, eager for her pending escape to starting college in the big city. She’s also chasing shenanigans wherever she can, including an overnight camping trip with her gal pals that has experimentation with hallucinogenics as the centerpiece. As her companions waft off in more expected bends of their minds, Elliott finds herself face to face with the future version of herself (Aubrey Plaza), some twenty years older. Even after the drugs wear off, Elliott manages to stay in touch with the older Elliot, receiving encouragement, warnings, and little tidbits about the societal changes that a couple decades bring.

Park wisely underplays the magical realism in her plot, emphasizing that it is there to provide a different angle on Elliott’s growth rather than gimmicky punchlines. There’s humor to be sure, and Plaza brings her crack timing and trademark beleaguered cynicism to her role in effective ways. Despite the gag built right into the title (which refers to the alias older-Elliott uses when she adds her contact information to younger-Elliott’s phone), Park is main concerned with striving for honesty with a wistful tinge. Nudged in certain directions by the vague forecasts and more pointed advice she’s given, Elliott strives with fitful success to be a better, more responsible and empathetic version of herself. Not all of Park’s plot points fully land; a revelation about the fate of the family farm doesn’t feel fully fleshed out, even as it it does get at a relatable point about how a childhood home continues to tug at a person even as they charge away from it. Still, there are more genuinely affecting moments — especially around family and young romance — than there are emotional misses.

Generally sure as Park’s storytelling is, My Old Ass is resonant because of the performance by Stella. A real find as a young actress, Stella plays Elliott with a completeness that puts believability to every one of her mercurial moods. She sidesteps the easy sullen teen stereotype and subtly shows how Elliott is a fundamentally decent, caring person, flash-pot bursts of teen angst notwithstanding. Through Stella’s performance, Elliott’s dramatic changes not only make sense but are mapped out by her bearing from the very beginning. Forget about the time travel; acting like this is the real magic.