One reason Sandra Hüller is one of the best actors working today, is that unlike many performers, she doesn't seem to care if you like her characters or not. Whether she's playing a tightly wound corporate climber in the brilliant comedy Toni Erdmann or a Nazi commandant's wife in the upcoming drama The Zone of Interest, you never once catch her pleading for the audience's sympathy.

That fearlessness is partly what makes her so compelling to watch in Anatomy of a Fall, the absorbingly intricate psychological thriller that won the Palme d'Or at Cannes this year. Hüller plays a successful German-born writer, also named Sandra, who finds herself on trial for her husband's murder.

The movie begins at a chalet in the French Alps, where Sandra and her French husband, Samuel, live with their 11-year-old son, Daniel. Things are tense between Sandra and Samuel, as we can sense from the way he blasts his music while she's being interviewed by a journalist. The interview gets cut short and the journalist leaves; sometime later, Samuel is found dead outside in the snow, bleeding heavily from a head wound.

Did he fall or jump from one of the chalet's upper stories? Or was he pushed? The director Justine Triet, who wrote the script with Arthur Harari, never reveals the answer. The story is full of intriguing forensic details; Samuel's fatal fall is diagrammed from every possible angle, and every spatter of blood is analyzed obsessively. But ultimately, Triet is less interested in explaining whodunit — or if anyone dun it — than in conducting an autopsy on Sandra and Samuel's marriage.

When Sandra is tried for Samuel's murder, the history of their troubled relationship comes to light. We learn that Samuel never forgave himself for his role in the accident years ago that left Daniel severely visually impaired. That took an obvious toll on the couple.

At one point, Samuel's therapist takes the stand and testifies that Samuel had described his wife as cold and controlling. But Sandra pushes back against this assessment, saying, "If I'd been seeing a therapist, he could stand here, too, and say very ugly things about Samuel. But would those things be true?"

I don't know how accurate Anatomy of a Fall is in its portrayal of the French legal system. But here, as in last year's excellent courtroom drama Saint Omer, it appears to be an extremely different system from ours, more tolerant of extended discussion. At one point, in a scene that even the movie seems to find hilarious, the overly aggressive prosecutor starts mining Sandra's own books for evidence, briefly turning a criminal trial into a literary debate. Still, Sandra's career is hardly incidental to the case. Samuel was also a writer, but a much less accomplished one than Sandra, which may have made him jealous.

Could Samuel have killed himself in despair? That's the possibility put forth to the court by Sandra's attorney — well played by Swann Arlaud — who doesn't seem entirely convinced of his client's innocence. Daniel, piercingly played by Milo Machado Graner, also doesn't know what to believe, as he's torn apart by the loss of his dad and possibly the loss of his mom.

The movie's emotional centerpiece is a stunningly written and acted flashback to a furious marital argument that took place shortly before Samuel's death — one of those knock-down, drag-out fights where every source of tension and resentment gets dragged to the surface. They clash over their finances, their differing approaches to parenting, their unsatisfying sex life and Sandra's past infidelity. Sandra expresses her frustration at the many sacrifices she's quietly made, including agreeing to live in France.

Anatomy of a Fall persuasively suggests that every marriage is ultimately something of a mystery. The fact that Samuel is no longer alive to defend himself makes it even harder to determine who here is telling the truth. Even so, I couldn't help but gravitate toward Sandra's side. There's something refreshing about the cool pragmatism she shows in the face of Samuel's insecurity, the way she refuses to short-change her career or coddle her husband for his failures. I left admiring Sandra's steely resolve, while still wondering if that resolve might have led her to do the unthinkable.