“You’re Killing Me Susana” could lose its audience pretty easily in a lot of ways.

When we open, Eligio (Gael García Bernal) is tip-toeing drunkenly and “quietly” so as not to wake his “sleeping” wife — not that that stops him from trying to rouse her for some late night action. When he awakes the next morning, she’s gone. And soon he finds out she doesn’t plan on coming back.

From the start, it’s clear Eligio is no hero to the story: He’s got a mistress at work, he comes home drunk and ready to drink more with his friends and doesn’t even notice that his wife has left him for a whole day. His lack of self-awareness makes his actions erratic, almost random. It’s the sort of thing that could all too easily slip into a perfunctory performance of plot contrivances in the hands of an actor other than Bernal. But with Bernal in the driver’s seat, Eligio comes to life.

His sputtering starts and stops to find his wife and win her love ultimately shape the arc of the movie, navigating hairpin twists and turns of emotional states that Bernal connects effortlessly.

When they eventually taking us to Middlebrook University in Iowa, where Susana (Verónica Echegui) was accepted into a prestigious writing program it’d, again, be easy to lose the thread of humanity. Leaving behind his native Mexico and his job as a soap actor, Eligio wrestles with his marital passion and his zest for machismo. It would be so easy to find Eligio’s flitting about as illogical.

But again the performances of Bernal and Echegui save the day. The duo paints out the dots of the dysfunctional relationship with fine strokes, before connecting every dot with an almost achingly familiar rhythm. Their fitful behavior becomes sympathethic, even understandable almost immediately as they find themselves in each other’s orbit.

Director Roberto Sneider smartly plays the direction low-key, letting the heat of the moments shared between Susana and Eligio speak for themselves in the frigid Iowa winter. Sometimes his style can verge on frustratingly muted; his camera allows for an access point, but little else. It almost feels like Sneider sits back and lets everything the couple shares and hides — the passion, the fights, the resolution — and lets it speak for itself.

But it’s hard to argue with intimacy like Susana and Eligio share; the link shared between these two wildly flawed characters makes for engaging fare even as it sometimes repeats itself. While there are comedic moments, this is no simple rom-com. Sneider lets the natural timbre of the full spectrum of a relationship shine through; there’s room for laughs and tears alike to breathe on their own. Points are made, sympathies switch, and somewhere in between it all Eligio grows. What could be simple formulaic indie-movie hogwash feels new. Somewhere in all its mayhem and back and forths, it finds a love story, a solid arc for the audience, and Susana.

‘You’re Killing Me Susana’ screens March 17-19 at SIFF Film Center.