Sovereign has a plot that could be ripped from today’s headlines. In fact, it’s based on a true story from the 2010s. It zeroes in on one man’s discontent with the government and how that festers and turns into violence. The film is empathetic and features stellar performances, but it is also muted and frustratingly inert.

Teenage Joe Kane (Jacob Tremblay)—a quiet, shy, and perceptive boy—worships his widowed father, Jerry (Nick Offerman). Jerry is a member of the sovereign citizen movement, which essentially means he believes there’s a distinction between his true self and the persona created by the government through legal documents (deeds, mortgages, Social Security cards). That persona is the “straw man.” The real you, Jerry insists, has the right to resist. He does this by substituting words: Homes are “domiciles,” cars are “conveyances,” thereby sidestepping pesky requirements like vehicle registration—and, more importantly, taxes. We watch his frustration build when the bank won’t accept his self-devised legal documents or when a hotel refuses to take cash. Jerry is often on the road, speaking in hotel conference rooms and church basements to fellow frustrated citizens, leaving Joe to fend off sheriffs arriving at their home to serve foreclosure papers.

Eventually, Jerry is arrested and spends a few days in jail. During that time, Joe is sent to a school run by social services, where he experiences a freedom he’s never had and begins to question his father—just as Jerry, once so sure of his mission, is facing mounting hardships. Tremblay is fantastic here. He has very little dialogue and often serves as a sounding board for Jerry, but you can see the vivid intelligence in his eyes and his slow, steady shift toward independence.

Meanwhile, Dennis Quaid plays Sheriff John Bouchart, who plants the first seeds of doubt in young Joe’s mind. He’s tough on his son, a fellow officer, though—just like Jerry—John clearly loves his child. Writer-director Christian Swegal weaves this subplot into Jerry’s story as a counterpoint, culminating in a visceral, albeit contrived, confrontation.

The scene is set and, as expected, the screws tighten around Jerry: He loses his home, his seminar audiences dwindle, and his rhetoric grows darker. Occasionally, cracks appear in Jerry’s self-assured façade—moments of tenderness with his son and his girlfriend (Martha Plimpton) suggest there’s more beneath the surface. However, most of his dialogue revolves around the legal fictions he clings to, which eventually becomes repetitive. Fortunately, Tremblay embodies Joe with nuance. He spends much of the film observing and, like many kids with domineering parents, begins pushing back in search of identity. Tremblay (Room) is one of those rare actors who gives viewers everything simply by listening. You feel Joe’s love for his father, his desire to escape, and his insecurity—all of it is there in a standout performance.

The film’s main issues lie in tone, pacing, and the script. There’s rarely any elevated dialogue or action, and the script doesn’t quite make that stillness compelling—especially in the back half, where smart characters begin acting irrationally, leaving viewers with too many questions. Offerman’s Jerry comes off as a cipher, which becomes more apparent as other characters feel fuller and more lived-in. Also, the film takes the slow build to a frustrating extreme, making the same points repeatedly. It’s disappointing because Sovereign has a lot going for it: excellent performances and a topical, well-researched subject. But there’s an indie earnestness that dulls its impact. Ultimately, it could use a bit more oomph.