It’s not an easy thing to keep an audience suspended between sympathy and revulsion for a character, but writer-director Alex Karpovsky (best known for his recurring role on HBO’s Girls) and co-screenwriter Garth Donovan do just that in the unsettling, tough-minded Rubberneck. The film kicks off with an almost meditative feel as it introduces us to Paul Harris, who works in a science lab, and Danielle (Jamie Ray Newman), the new coworker with whom he has a one-night stand. A low-flame tension and sense of dread kicks in when Danielle makes it clear that nothing more is to come of the hookup, and Paul immediately becomes unhinged. Initially his response is just creepy and discomfiting, but when Danielle begins an affair with another colleague, a married man, Paul’s jealousy shifts into an escalating mental breakdown that leads to stalking, meddling in the married man’s marriage, and a shocking act of violence. Karpovsky and Donovan, who say the film is “inspired by true events,” give Paul a painful backstory (slowly teased out and given its own shocking twist) to explain the root of his neediness and despair, but they never pass it off as justification for his actions. Instead, as the story twists to the rhythms of Paul’s meltdown and increasingly horrific acts, the audience is left to make of all this what it will. (The use of music in the film is wonderful in this regard; sparse and sparingly employed, it gives no cues on what emotion you should be having.) Karpovsky is unsettlingly good as Paul, and Newman’s Danielle is sexy and layered. Her appeal—and the fact that she’s out of Paul’s league—is obvious, but on a recognizably human scale. And that’s what gives the film its resonance, that Paul is revealed to be monstrous, but not exaggeratedly so.