There’s a more interesting story lurking in Jan-Eric Mack’s “The Happy Family” than what’s actually told. At times, the Swiss filmmaker teases the possibility that the conventional narrative shown so far could take a bold and daring turn. It’s a broken promise, though, and those glimpses of something thornier and more daring ultimately seem like signs that a filmmaker isn’t in full control of his plot. The first Swiss film to compete in the Crystal Globe at the Karlovy Vary Film Festival, “A Happy Family,” is a custody drama that turns out to be more interested in the “drama” part of the phrase, at the expense of verisimilitude.

Still, Anna Schinz impresses from the start as Nicole “Niki” Hofer, a single mother of two already struggling to satisfy child protective services in the film’s opening scene. Cinematographer Yunus Roy Imer previously filmed “System Crasher,” Nora Fingscheidt’s explosive portrait of a difficult child navigating the foster care system, and the same naturalism and attention to the slightest mood swings is on display here. But what Mack actually intends to show through this aesthetic is less clear.

It’s obvious in the scene that Niki loves her kids, but it’s strange that she makes them eat cereal without milk in front of the caseworker watching them that morning. Perhaps the visit was unannounced; Even so, Niki’s lack of preparation remains quite confusing when in the next scene we learn that she has already received several visits from social services. This time, she is even told that her youngest son is getting sick and having difficulty concentrating at school due to malnutrition. There is a lot at stake.

Niki works two jobs, at a laundromat and at a bar, and money is tight. But when tragedy nearly occurs and the children accidentally set the apartment on fire while she is at work, the film itself makes no effort to identify economic precariousness as the true cause of the disaster. In a meeting with social workers placing Niki’s children in foster care after the incident, the angry mother explains that she did not receive her daughter’s distressed phone calls because her cell phone battery was dead at the time. This excuse becomes even more shocking when Niki blames her kids for the catastrophe: her phone ran out of battery because the kids played too much earlier that day.

The film, however, does not question or even acknowledge Niki’s lack of self-awareness. More interested in the mechanics of melodrama than in developing a solid perspective or commentary on its protagonist, “A Happy Family” builds a comic rhythm in the back-and-forth between the defensive mother and her interlocutors. The scene ends with a hard cut as Niki staggers toward one of the social workers, and the rest of the film maintains this light-hearted tone as she eagerly embarks on a wild adventure to return to (and eventually kidnap!) her children.

However, this lightness continues to clash with Niki’s immaturity, in that scene and beyond; Still, his youthful lack of perspective is dramatically compelling. There are moments when “A Happy Family” seems not to be the family story of a tough mother fighting the system, but rather an interrogative piece. As it progresses, the film reveals through intriguing details of dialogue and acting the deep personality flaws of a protagonist who initially seems less dangerous than she turns out to be. On several occasions, Mack’s filmmaking signals that Niki is going too far: some of the most exciting, high-octane moments of her incredibly irresponsible mission are punctuated by sinister tunes that contrast starkly with her enthusiasm.

But Mack and his co-writers, including Schinz, never connect the dots. Although everything suggests that Niki, in her reckless behavior, is at least partially responsible for her own situation, “A Happy Family” stops short of addressing this idea. Instead, the film concludes with Niki’s banal statement about poverty driving people to extremes, something that is not entirely confirmed by the reality of the story. Another recent film that explored remarkably similar dramatic and thematic territory, Daisy-May Hudson’s “Lollipop,” better humanized and problematized its complex female protagonist, situating her plight within a broader socioeconomic context, while never losing sight of the specific details of her experience and personality.

Here, Niki’s impulsiveness is romanticized, her lack of foresight is excused, and her temper is explained: the only way to make sense of the film’s perspective on her is to imagine her as the clichéd working-class mother with a heart of gold but who simply doesn’t know any better. It’s to Schinz’s credit that Niki ultimately seems like a much more human and interesting figure than that.